Build a Full Game with Claude Code (Story, Voices, Ending)

Author: Leon van Zyl · Watch on YouTube

Video authored by the channel shown, not by IANIA; all rights belong to the creator. Transcript and summary generated automatically; the original-language content is preserved.

Original language: English

Original video: Build a Full Game with Claude Code (Story, Voices, Ending) · Channel: Leon van Zyl · 24:23 · Watch on YouTube

Topics: AI agents, Claude Code, Software engineering with AI, AI content generation, Multimodal models

Summary

Leon van Zyl presents a 10-step workflow for using Claude Code to build a complete, browser-based horror game with a story, characters, voice acting, music, sound effects, and an ending. He explains how to develop the story and art style, create debugging tools and audio, and refine an initial playable slice with feedback from critic agents. After completing and testing the game, he demonstrates deploying it online and shares a free agent skill and prompts. The video ends with a gameplay excerpt from the finished game.

Key points

Start with a high-level game idea and collaborate with Claude to develop the story, characters, locations, scares, and ending.
Store project information in documentation so Claude can refer back to it across sessions.
Have Claude build debugging tools that allow it to inspect specific scenes, characters, and objects.
Explore several visual styles with mock-ups, then record the chosen look in a style guide.
Generate voice acting, music, and sound effects with ElevenLabs or ask Claude to create audio assets.
Prototype character dialogue with facial expressions and lip sync before committing to the full game.
Build a vertical slice and review it with a tough critic, a scare director, and a narrative agent.
Play the slice, note problems, and ask Claude to complete the rest of the game using the established guidelines.
Polish the full game by testing it from start to finish, checking device performance, and incorporating feedback from another player.
Deploy the web game through a hosting service and Claude Code’s Hostinger connector.

Chapters

Start	Chapter	Summary
00:00	The project and game preview	Leon introduces the goal of building a complete cozy horror game with Claude Code and previews its story, music, voices, and sound effects.
02:04	Developing the story and setting up Claude	He explains the Claude Code setup, subscription expectations, and how to brainstorm the game’s story, characters, mechanics, scares, and ending.
04:09	Debugging tools and visual style	Claude is given tools to inspect scenes and check object placement, then creates visual mock-ups that the creator can refine into a style guide.
07:14	Audio, character performance, and lip sync	He describes generating audio assets, previewing character voices, and testing facial expressions and lip sync in a dialogue scene.
09:48	Build and review a vertical slice	Before making the full game, he recommends creating a short playable version and evaluating it with agents focused on criticism, scares, and narrative.
11:51	Complete and polish the game	After testing the slice and listing fixes, Claude builds the rest of the game, which is then checked for issues such as lighting, audio, and device performance.
13:25	Deploy the game online	He demonstrates using Hostinger’s Claude Code connector to deploy the game and make it available at a shareable URL.
15:32	Gameplay excerpt	The video plays through a portion of the finished game’s story, following the band through its last performance and the strange events that follow.

Quotes

This game has a real story, characters with backstories, voice acting, music, sound effects, and a proper ending with credits. — 00:00

what we’re asking Claude to do here is to build its own debugging tools. — 04:40

what I recommend you do at this point is to create a vertical slice of the game. — 09:48

I also told Claude not to wait for me for small decisions. — 12:22

Finally, it will give you a working URL to your game. — 14:58

Concepts and entities

Claude Code, Opus 5.5, ElevenLabs, Hostinger, Leon van Zyl, vertical slice, agent skill

Full transcript (original language)

00:00 In this video I’ll show you how to build any game using Claude Code, and I’m not talking about another Minecraft clone either. This game has a real story, characters with backstories, voice acting, music, sound effects, and a proper ending with credits. Since it’s the spooky season, we’ll build a cozy horror game. But the steps I’ll show you in this video can be used to build any game, and you do not have to be a developer to follow along. I’ll take you through my 10-step workflow, and I’ll show you how to put your game online so anyone can play it.

00:32 As a bonus, I’ll give you a free agent skill that does all of this for you. But first let me show you a few snippets from the game, listen to the music, the voice acting, and the sound effects. Rob. Rob! We nailed it! That was a good one. Who’s the old fashioned for, Bernie? My sister. Every year. Old habit. And no wishes under the bell tonight.

01:02 Any of you. It listens. Ooh, spooky. I mean it, Douglas. So, eight years. Eight years, four vans, one fire. Small fire. And I’m going to miss this so much. It’s stupid. To the last song. To the last song. Come on. It’s just a band.

01:34 It’s not just a band. Mags? Dougie? Hello? No signal. And it’s still 11:59. Mags was texting me. She was right across the table. How cool is that? Although we’re building a game in this video, you’re actually going to learn a lot of really cool lessons along the way. I hope you’re excited, so let’s get started. Now, as I mentioned, I will be using

02:04 Claude Code in this video. In fact, I’ll use Claude running in the desktop app. And for the entirety of this video, I’ll only use Opus 5.5 running on extra effort. You’re more than welcome to drop down to high as well. You’ll still get really good results. So, create a new session in Claude Code and then select a folder on your machine. Now, first, I do want to set expectations here. What we’re asking the agent to do is super complex. If you want the agent to create a game that actually includes sound effects, voice acting, and characters that

02:36 actually have lip sync to the audio, this is going to take a lot of time. I would not recommend trying to pay for this using API tokens. You definitely need a Claude subscription. Even if you’re on a $20 plan, that’s perfectly fine. You’ll hit your limits. Wait for the limits to reset and Claude will automatically continue. Now, the first step in the 10-step workflow is to flesh out the story, the characters, and the locations. So, this is the prompt I would use to start this process. So, we’re telling Claude that we want to build a cozy horror game

03:08 or, you know, a first-person shooter, whatever you want to do, then we can describe our game idea. Now, you don’t have to flesh out the entire story. Personally, I’m not really good at writing detailed stories myself. So, just give a high-level idea of what you have in mind. And Claude will help you brainstorm ideas for your game. So, simply copy that prompt and add it to the chat. And by the way, you can download all of these prompts for free and the agent skill that does all of this for you from the description in this video. Now, I’m not going to sit here for a day building this game again.

03:38 So, that will give you something like this. So, Claude will propose a script for your video. So, it kind of gives you the high-level story idea. It lists all the characters with their backstories. It will give you, like, the main gameplay mechanics. And it will propose the main scares as well as the ending. Now, at this point, you’re more than welcome to make any changes you want. Like, rename the characters, change the backstory, maybe introduce your own custom scares. This is your opportunity to work with the agent to bed down your game.

04:09 Once you’ve locked in the story, Claude will store all of this information within the docs folder of your project folder. So, if this conversation ever had to get compacted or you want to create a new session, Claude will be able to reference these documents to figure out what the game is about. The second step is to set up the game environment for Claude. Now, Claude cannot play the game the same way that you and I can. It’s impossible for Claude to analyze the game at 60 frames a second. Also, if Claude had to test a specific section in the game,

04:40 it shouldn’t have to play the entire game from beginning to that section in order to debug something. So, what we’re asking Claude to do here is to build its own debugging tools. That way, it can jump to any point in the game to debug a specific scene, view a character, view an object, etc. Every time Claude, it should measure that nothing is floating or poking through anything else. You’ve probably seen it where it might design a coffee table and then the coffee cup is like on the floor or it’s actually floating in the air. So, it’s going to analyze a scene from

05:11 different perspectives, ensuring that everything is actually aligned and it looks correct. Now, visually, this step is not that interesting. This is basically Claude setting up its environment for success. The third step is where things get really interesting. In this step, we create the art style of the game. We ask Claude to create three different ideas, so three totally unique mock-ups of what our game could look like. You are more than welcome to ask it to create more variations to try different ideas. So, let me show you what that actually looked like for my project.

05:41 Claude came up with these three styles. Wurly, Paper Crowns, and Last Call 98. I then asked Claude to create a fourth variant, which was called Grounded Realism, going for a more realistic look. So, Claude created these different screenshots to kind of show what the game could look like. It will even give you this interactive mock-up. So, this way you can get a really good idea of what this is going to look like in motion. It will give you like different perspectives, so we can go to first person, to turntable, so we can

06:12 view the actual characters. And I personally like this style the most. This is a little jittery style. Let me just show you what the others look like as well. So, this is the Paper Crown example. And this one was Last Call 98, which seems to mimic like this PlayStation 1 style. And this is what we got for Grounded Realism. So, this is a really fun stage. This is now where you can work with the agent to, you know, maybe fix one of these designs or iterate on it or improve it. In fact, after looking at this design, I decided to change my

06:42 character from male to female. You can paste in this prompt. So, you can just tell Claude that you want to pick this specific style and then turn that into a rulebook for the look, the colors, the materials, characters, shapes, lighting, animations, and menus. So, Claude will actually take that style and store it in that docs folder. So, by doing this, Claude will honor the art style whenever it creates new props or characters in our game. The fourth step is where we focus on audio, like the voice acting, the music,

07:14 and the sound effects. Now, this step is optional. I use ElevenLabs to generate all of these audio assets. Now, to be clear, I’m not sponsored by ElevenLabs. I just found it very convenient for working on this project. There are local open source alternatives that you can use as well. So, at this point, you basically have two options. If you do not want to pay for service like ElevenLabs or generate it locally, simply ask Claude to create the sound effects itself. But if you do want to follow along with ElevenLabs, simply go to elevenlabs.io and

07:45 then sign in to your account. Then scroll down to developers, go to API keys, then create a new key, give it any name you want, and disable restrict key. So, then click on create key and copy your key. Then what you can do is simply copy this prompt and paste it into the chat. Then also tell Claude what your API key is. Or if you want to be secure about it, simply open up a .env file in the project folder and drop your API key in there. Claude will then create this page for you.

08:16 This is where you can listen to the different voices, casting, sound effects, music, scares, and all voice lines. I’ll play a few samples.

08:46 If you do not like the voice that Claude selected for any of these characters, you can tell it to use a different voice. Now, this step is really cool. When a character speaks, I actually want them to emote, and I do want their lips to move in sync with the actual audio. So, what you can do is actually copy this prompt and pass it to Claude. We’re asking Claude to create a demo with the main characters talking, and that will result in the scene. I will push up the audio in a second, but this is the first time we can actually hear the background sounds,

09:17 and we can see our character close up, and we’ll be able to see what the facial expressions and lip sync looks like. To the last song! To the last song! “I wish it wasn’t. Come on, it’s just a band.” “Mags? Dougie? Hello?” I mean, how cool is that? You can actually see the different facial expressions in action as well. And because we’re working with Claude,

09:48 if you don’t like something, ask Claude to adjust it. Once you’re happy with the scene and sort of what the character looks like and the animations, it’s time to lock it in. Now that we’ve got our audio and we know what our character is going to look like, we might be tempted to just jump ahead and ask Claude to build the entire game. But what I recommend you do at this point is to create a vertical slice of the game. It’s just enough of the gameplay for us to review it and fine-tune and fix anything we don’t like. We’re asking Claude to build a short version of the game

10:19 that includes the characters, the scares, the sound effects and everything else. But we’re also spinning up critic agents. And each of those would focus on a specific area of the game. What I like to do is to introduce three agents. A tough critic, a scare director, and a narrative agent that will ensure that the game is aligned with the original story. The scare director will focus only on the scares, the jump scares, the horror scenes, to make sure that they are actually scary and spooky.

10:49 And the tough critic will focus on everything else, like the gameplay, the graphics, animations, etc. And Claude will work away. It is going to take a bit of time, but eventually it will give you a link to the actual game or a slice of the game. We’ve got our main menu, we even have options, and well, let’s actually just jump into the game. Again, this is not the entire game, but we can already see our character in motion. We can control the character. We are looking into a mirror. And we’re in this little bathroom of a pub.

11:20 It might be a little bit soft on your end, but there is like background music, there’s audio playing. We can’t leave the bathroom, so let’s actually use the sink. It’s just a bear. I’m just a bear. Our character is actually speaking, she’s emoting, her lips actually moved as well, which is exactly what I want. You can see in her facial expression that something is indeed off, and the expression just changed. Let’s leave the bathroom, and that looks really cool. So she just brought up her phone, and I really do not like

11:51 the way the phone looks. So in the final version of the game, you’ll see the phone is an actual 3D object. So step seven is to play that vertical slice, play it a couple of times, and note down anything that needs to be fixed and give it to Claude. Once you’re happy with that vertical slice, it’s time to lock it in. Ask Claude to build the rest of the game. So in this point, we’re telling Claude to continue with the rest of the game, and we’re reminding it to use our team, so the three critic agents. I also told Claude not to wait for me for small decisions.

12:22 It can make decisions itself. The reason for this is this is most likely going to run for like 12 hours or even a day. So I did not want the session to stop, because I wasn’t available. I’m not going to play the game right now, I’m going to add a section at the end of this video and play like the first few minutes. But this game is online if you do want to try it yourself. Step nine is the final polish. Play the game from start to finish and let Claude know what needs to be fixed. Like I noticed the lighting wasn’t really spooky enough in certain scenes,

12:53 so I asked Claude to fix it. Since this game is running in the browser, you need to optimize it for different devices. Like this game should be optimized to run on pretty much anyone’s laptop. In my version, I also noticed that some of the voice acting was missing, or Claude actually played the wrong audio file in certain scenes. Of course, those were small fixes and Claude was able to fix it within minutes. Of course, this final line is not really part of the prompt itself, but if you can, ask someone to sit next to you and to play the game themselves. I actually asked my wife to play the game

13:25 and to give feedback as well. And what’s the point in creating a game if no one actually plays it? So step 10, we’ll put our game online so anyone can play it. To deploy the game online, you will need to use a hosting service. I prefer to use Hostinger and they’ve been a long-standing partner with this channel. I’ll leave a link to this page in the description. So what you can do is choose one of their plans, like this unlimited plan at only like $4 per month. You can choose your term between 1 month, 12 months, 24 months, it really doesn’t matter.

13:56 And the cool thing about this package is you are able to host multiple domains and multiple websites on this account. So select your term, you also get a free domain, so you can just search for your domain and register it. That way your game has a unique URL. Hostinger will give you an additional 10% off if you use my coupon code. So enter Leon hosting and click on apply. And then you can simply continue to checkout. Now that we have our hosting account, it’s really easy to deploy any web app. We’ll use the Hostinger connector within Claude Code.

14:27 So within the Claude desktop app, simply go to connectors, go to manage connectors, then go to discover and simply search for Hostinger. And then search for this official Hostinger connector. Then from here, simply click on add. And now you have the Hostinger connector set up. So now we can simply copy this prompt that tells Claude to use the Hostinger connector to deploy our game online. The first time you use this connector, Claude will ask you to authenticate your Hostinger account, which is really simple. Just follow these instructions and Claude

14:58 will go ahead and deploy your project. Finally, it will give you a working URL to your game. And anyone with this URL can play my game. As promised, I created an agent skill that does all of this for you. You do not have to manually copy and paste prompts around. You can download the skill for free and I’ll link to it in the description of this video. So I’m going to end this video by playing a few minutes of the actual game. But of course, you can play the game yourself and I do want to hear your thoughts. [VIDEO PLAYBACK]

15:32 One, two, three, four. [VIDEO PLAYBACK] [MUSIC PLAYING] Turn the lights down Sing it loud

16:03 Last song, don’t think, just count. One more round One more round Before they turn the lights down Sing it loud Sing it now Last chorus ever, Rob, no pressure. One more round One more round You’re rushing. I’m not rushing, I’m a little rushing.

16:36 One more song. Hold on Hold on the crowd Before they turn the lights down Sing it loud Sing it now Bring it home, drummer. One more round One more round Before they turn the lights down Sing it loud Sing it now

17:08 One more round One more round Rob, Rob, we nailed it. That was a good one. (crowd chattering) Silverbell, you have been gorgeous. We’ve been the Paper Crowns, and that, sadly, was our last song ever. Don’t cry, Dougie. It’s the Tom and Jerry. Priya on keys, Dougie on bass,

17:41 and on drums, the heartbeat of this sorry outfit, Robin. Merry Christmas. Get home safe. And, Bernie, I believe you owe us a round. Get over here before I change my mind. Eight years. That’s it. That’s the whole thing. Great set, hun. Oh, sorry. Just gonna squeeze past you there. Did you quit? Who’s gonna play my wedding? Merry Christmas, Paper Crowns. Drummer, hey, what was

18:13 that last one called? There’s my band. You were wonderful, hun. All of you. Four Tom and Jerrys. On the house. Don’t tell the IRS. On the house? In this snow, they’ll slide right off. Every year, hun. Every year you say that. Bernie, marry me. Get in line. Who’s the old fashioned for, Bernie?

18:43 My sister. Every year, old habit. And no wishes under the bell tonight. Any of you. It listens. Ooh, spooky. I mean it, Douglas. Encore, one more. Typing, typing, deleting. Typing, deleting. Mags, no phones at the table. Sorry, sorry. Nearly, nope, later.

19:14 She starts the tour in January. Nobody said it out loud all night. Not even me. Okay, okay. Grandma’s crackers. Rob, grab an end. Crowns on. It’s the law. What do you call a night that never ends? Oh, it’s torn. The punch line’s gone. My 20s. A sound check.

19:44 No, it’s gonna bug me. I’m gonna lie awake. So, eight years. Eight years, four vans, one fire. Small fire. And I’m going to miss this so much. It’s stupid. To the last song. To the last song. To the last song. I wish it wasn’t. Be right back. Don’t fall in.

20:15 Hurry up. It’s nearly midnight. Wash up, then back to the band. One more minute.

20:50 Breathe. The mirror. Have a proper look at yourself, Robin. Guys? (phone ringing) Mags? Dougie? Hello? No signal, and it’s still 11:59. Mags was texting me. She was right across the table. My sticks are still on the kit.

21:20 Dead, not even a dial tone. (phone ringing) Hello, old friends. That skip, it’s keeping time. Keys, Bernie? Is that you? No.

22:02 To the last song. I wish it wasn’t. That was me. It listens. Bernie said it listens. I’ll keep it safe for you, Bernie. (soft music)

22:47 That one’s looking at me. Again. I want to see them again. (soft music) It was right there. Where did it go? One more, count it in. Four on the beat again. Right here’s fine.

23:19 Four on the beat, Robin. Even just clicking the sticks. (soft music) It walked right up to that door and stopped. Frost indoors. The payphone, it was dead a minute ago. Hello? Oh, thank goodness. Someone new.

23:49 Listen, hun, there isn’t much time. Well, there’s all the time in the world. That’s the trouble. Don’t let him hear you play out of time. Find your friends. The bits of them still here. Quick as you can, darling. What’s left of tonight won’t keep forever. Then come and find me. I’ll be at the piano. I’m always at the piano. Him, the tall one, the one that was looking at me.

24:23 Whoever that was knows this place and Bernie keeps everything in her office.