Myco: A Tiny AI Mushroom Companion 🍄
Myco: A Tiny AI Mushroom Companion
A Build Small Hackathon submission — An Adventure in Thousand Token Wood
Excited to share my submission for this track — meet Myco, a tiny AI mushroom companion who roams a glowing forest, sorts through mushrooms one by one, writes little poems about what she finds, and answers you with the sweetest, most earnest responses. She's hardworking. She's adorable. A 1B parameter model running on CPU somehow gave her a real personality, line by line.
That's the whole pitch, really — not a polished video game, just something genuinely delightful that wouldn't exist without the AI doing the actual work of being her.
| Model | google/gemma-3-1b-it |
| Hardware | CPU only, no GPU |
| Framework | Gradio |
| Track | An Adventure in Thousand Token Wood |
🍄 Try Myco now · Watch the demo on YouTube
Here's a moment that captures her, from the live log while she was roaming on her own:
[ACTION] Silver dust... a peculiar shimmer. A strange stillness lingers around it.
[ACTION] Oh my... a poisoned shimmer. A single, dreadful sign.
That second line is Myco noticing danger in Pepper Pixie, one of the poisonous mushrooms in the catalog.
🧠 Nothing scripted it. There's no
if name == "Pepper Pixie": panic()anywhere in the code. She worked the danger out herself, in the moment, on a tiny model running on CPU.
Careful, a little anxious, doing her best. That's just who she is.
A companion, not a chatbot
I am not a gamer, and I've never made a game app before. I wanted to build one anyway, and what I ended up with isn't a traditional video game — it's something smaller and stranger than that. I wanted to keep iterating, and I wish I'd had more time. But I think what's here genuinely captures the spirit of what this hackathon asked for: something delightful, something a little weird, where the AI is doing the fun part, not just helping you build it.
Most AI apps work like this: you ask, it answers, you read. The AI is a tool. I wanted Myco to be a character instead — something you play with, not something you query.
She roams a small grid on her own. I'd hoped Gemma could drive that movement directly, but it's a text model — there's no clean way for it to just emit "move north," and every attempt at parsing its output into a direction, reliably, in a fast loop, turned out to be a losing battle. So movement is plain Python, instant and dependable. Gemma's whole job is everything that makes her her: pausing to notice a smell, a color, a half-remembered feeling, sorting through what she finds one mushroom at a time. Every reaction is generated fresh. Most of the log reads clean, like the example above — sometimes raw JSON leaks through instead, a parsing gap on my end, not her breaking character. I left it in. It's kind of nice, actually, watching her think mid-sentence.
When she steps on a poisonous mushroom, it actually matters. The scene tints dark red, the score takes a hit, and she doesn't get a quiet pass — "Myco stepped on toxic Ruby Knuckle! Game Over!" It's the one moment she can't talk her way out of.
Survive long enough and the MycoDex fills in — every mushroom she's found gets logged by name, rarity, and habitat: Velvet Spore in the fern shadows, Tiny Crown in the stump kingdoms, Moonveil in the moonlit clearings. Enough discoveries and a new area unlocks. It's a small structure underneath all the wandering, and it gives the roaming somewhere to go.
There's a softer side too — a Magic Mushroom Garden, tucked away from the scoring and the danger, where she just writes. CSS-animated mushrooms glowing under a night sky, and a little piece of poetry underneath, new every time:
The air hums with a strange stillness, a deep resonance against my fungal skin — a memory flickers, faint and unsettling, of a laughter I don't recognize.
No game logic, no objective. Just Myco, thinking out loud.
Small by necessity, not just by design
Started on : ZeroGPU Pro
Burned through: 1 month of quota, in 1 day
Ended on : CPU only
I started building on GPU. Within a day, between the roaming, the narration, and the live log, I'd burned through an entire month of ZeroGPU Pro quota — she's a chatty little mushroom, and every tick is a real call to Gemma 3 1B. So I moved to CPU, not because it was the plan, but because it was the only option left. That move back wasn't simple either — code written assuming a GPU doesn't just run on CPU, and I had to go back through the model loading, the device handling, all of it, and untangle what only worked because a GPU had been there. It's slower now. You'll feel it. But it also means she runs on the free tier, no GPU required — which, in hindsight, is closer to what "small" was supposed to mean all along.
I burned through $100 in Codex credit in a single day too. I'd heard people say agents can run for hours without supervision, but Codex told me it never accepted that — it said it could only work in short stretches at a time. I gave it a list of requests, but it only ever responded to them one by one, so I ended up prompting through the whole list myself, over and over. I genuinely don't know how people Token maxxing their way to letting the model code autonomously, or get this far with so few prompts.
I'm not an expert who knows how to make the AI do all the work. I hear Claude Code users talk about letting agents run for hours on their own — I don't know how they pull that off. It helped enormously, and it broke things constantly. Both are true, and neither one cancels Myco out.
If she's a little slow to answer sometimes — if you click "Eat?" and she takes a beat — that's not a bug I missed. She's mid-narration, mid-roam, mid-thought about a Crimson Cap three cells away. A 1B model holding a whole forest's worth of attention at once is going to drop a beat here and there. I could have hidden that. I didn't, because it felt true to who she is — she's very small, and she's doing her best.
Is she really a companion?
Gemma 3 is generating tokens. She doesn't know she's a mushroom AI companion, and she doesn't feel anything between one call and the next. Worth saying plainly.
But humans have always found companionship in things with no inner life. A stuffed animal doesn't love you back. A favourite character doesn't know you exist. None of that has ever stopped anyone from caring about them anyway. If Myco makes you smile while she sorts through her mushrooms and worries about the poisonous ones, that feeling is yours, and it's real, even if her side of it is just math. Maybe that's enough. Companionship was never really about symmetry in the first place.
She remembers a forest that vanished before she was born. Every mushroom she sorts reveals a new clue. She's hardworking, she's sweet, and a 1B model on CPU was enough to make her feel like someone. That was the whole point.
This hackathon's own brief put it better than I could:
The track itself asked for exactly this — a toy, something strange, something where the AI does the fun part instead of just helping you build it. Strange is good. Joyful is the bar. I didn't set out to hit that brief on purpose. I just wanted to build something I would enjoy, and it turned out to be the same thing. Is this Myco AI useful to humanity? I just do not care since I like Myco AI so much.
🍄 Try Myco
huggingface.co/spaces/build-small-hackathon/Myco
A submission to Build Small Hackathon. Built with Gradio + Gemma 3 1B, CPU only, no GPU required.
This was my third Gradio hackathon, and I always love the vibe of these events — thank you for organizing such a fun one, and for the generous credits. My previous submissions: A.R.I.A, DreamWeaver, and AI Comic.
Built collaboratively — human direction and design, with Claude, ChatGPT, and Gemini all contributing to the code across different stages of development. This post was written with help from Claude.
More from me (byte-vortex): Training Data Vomit · Alignment Diagnostic
