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SKZ-GOTCHI
Showing someone what a modern LLM / harness can do can be pretty hard. You show random demos, talk about how easily it did a refactor or some log digging, but capturing the magic of creating something from an idea really fast is a hard thing to do.
And yes, sometimes it's going to be a total AI slopfest, with the same UI elements, same texts, random missing features, etc. etc., but that can happen with humans as well — I do still remember Stack Overflow copy-paste reviews.
Anyway, my better half loves South Korean culture and bands, especially Stray Kids. Grabbing someone's sweet-spot topic for a vibe-coded project gets you almost halfway there. The other half is the idea, and if you pick the right representation, everything just snaps together.
I like doing 8bit / pixel art style GFX, since it hides most of the problems and gives 30-ish folks fond childhood memories, so there are some extra points in there. Since this is really a presentation of what technology can do, let me share my "master prompt" that yielded the whole flow, and how I worked from there.
Master prompt
Let's create a small tamagotchi game, where you can / should manage one of the Stray Kids singers. Include everyone in the game and make it entertaining.
Be creative, but truthful to the original game and characters. 8bit-like color graphics, and it should run on an M5StickC PLUS2 ESP32.
I want to have some music in the game and diverse minigames of some sort.
First step: create a DETAILED idea for the game. The device should be held upwards, which will make 240 x 135 for the playfield.
It has everything I just mentioned: the fun topic, the "anti-slopify filter" of 8bit, the nostalgic Tamagotchi factor and, of course, the "no mistakes" part with "make it entertaining". :D
This went into ChatGPT, and 23k characters later we got a decent Tamagotchi game skeleton: goal.md
Once this was ready, I just threw it into Z.ai GLM 5.1 with a "build it man" prompt and let that thread panic, for pleasure.
The other part of the grind was the graphics. A couple of prompts later, in the same ChatGPT session, I had a list of assets that I needed to grab for the game. At that time I did not have my image generator or ChatGPT image MCP, so copy-pasting prompts that ChatGPT generated into a new session, then grabbing the images from that session, took around 1–1.5 hours.
Since this was a late-night vibecoding session, I was watching something on the TV the whole time and just let this run in the background.
The results were great, but the image generator still cannot keep a nice grid for 8bit games, so that needed some extra code on GLM's side to crop the images.
Hyunjin
Once the characters were decent and every asset was generated, I connected the device itself and let it cook.
Once there was enough to see that we were heading in the right direction, I wanted some fine-tuning, a manual and so on, so v2 was born: v2.md. This was generated by Opus, since GLM is not that strong at planning, but great at execution.
Let me remind you that at this point, there had only been some light testing and the project had been started roughly 4 hours earlier. The timeline looks something like this based on git commits, once I started asking for those.
Background images and other assets turned out pretty decent as well:
Timeline of the project
26b8ca0 - Mon Aug 10 00:40:43 2026 +0200 : Illustrated manual (HTML + PDF) and v2 notes
b72b078 - Mon Aug 10 00:27:54 2026 +0200 : Browser build via Emscripten
685de90 - Mon Aug 10 00:17:51 2026 +0200 : QUICK MODE and an explicit reset
618d344 - Mon Aug 10 00:10:56 2026 +0200 : Fix a freshly reset pet being charged for every hour since the epoch
3253f40 - Mon Aug 10 00:08:02 2026 +0200 : Iteration 8: birthdays, collection screen, adaptive soundtrack
6ced6c8 - Mon Aug 10 00:03:57 2026 +0200 : Iteration 7: comeback week and the concert finale
b22ff29 - Sun Aug 9 23:54:16 2026 +0200 : Iteration 6: the remaining seven minigames
bc6ae7e - Sun Aug 9 23:43:25 2026 +0200 : Iteration 5: minigame framework and the three input-defining games
bad1ee2 - Sun Aug 9 23:33:57 2026 +0200 : Iteration 4: random event and dialogue engine
fe1cde9 - Sun Aug 9 23:23:36 2026 +0200 : Fix save being rewritten immediately after a wipe
8879a37 - Sun Aug 9 23:19:53 2026 +0200 : Iteration 3 (WIP): locations, daily schedules, activity scene
74f3594 - Sun Aug 9 23:07:57 2026 +0200 : Iteration 2: fix sprite transparency, all eight members, new locations
fbfa599 - Sun Aug 9 22:42:47 2026 +0200 : Pin upload/monitor port glob to /dev/cu.usb* so auto-detect skips Bluetooth
f0fbeee - Sun Aug 9 22:42:05 2026 +0200 : Iteration 1: playable dorm loop for M5StickC PLUS2
The next day
Testing, giving feedback and iterating on a project is the long grind. Almost everything so far followed the "simple" route of letting the LLM decide what to do, what is fun, and in some cases where to cut corners.
I tend to pick the simplest answer when something is vibecoded, and iterate on it later.
The result is OK, runs well on the device, and is somewhat fun-ish to play. But most importantly, it helped show how "easy" getting from an idea to a POC is nowadays.
The manual can be accessed here: PDF and HTML
And you can play the game here, but since it's a Tamagotchi game, the browser version is more like a POC than the real thing: game
There were some small(ish) features implemented since v2, including support for two extra languages — Korean and Hungarian — and wrapping it into an Expo app with shims, but nothing fancy.
TLDR
You can create fun projects from basically a one-liner, co-creating something that can be thrown away but can still create long-term inspiration for the next project.
And if it motivates someone to look into this crazy world as well, that's a plus.
Fan project / legal notice
SKZ-GOTCHI is an unofficial, non-commercial fan project made for fun, experimentation and as a technical demo. It is not affiliated with, endorsed by, sponsored by, or connected to Stray Kids, JYP Entertainment, or any related rights holders.
Stray Kids, member names, likenesses, trademarks, music, artwork and other associated intellectual property belong to their respective owners. This project does not claim ownership of any third-party intellectual property.