Depthbound · Augustus Forge

Why

I had $100 of Claude credits and a few minutes. The question was simple: how far can one AI agent take a real game from a single design document? Usually the calls are mine. This time I let the agent make them, and it logged every call it made on its own.

What came out

The whole loop works: main menu, hero select, camp, ten floors, two bosses, a final chest and back to camp. Every floor runs on a water timer, so you choose what to fight, what to loot and when to run. Twelve skills, gear in five rarities, autosave, English, Russian and Spanish.

The simulation is separate from the 3D view, so a bot plays floors faster than real time. It showed that the design document’s boss numbers were unwinnable, and they were rebalanced.

What broke

Animation. Every character shares one library of stock clips, and the rat is animated by code. My miss: I never pointed the agent at free mocap libraries.
Magic was left out on purpose. Unique spells and skill effects are where AI still can’t deliver, so that test moves to a cheap Roblox prototype.
It never ran on a real mid-range phone, and the balance was tuned by the bot, not by people.

The path

What I posted on X about it, oldest first.

4 Oct 2026Result

$100 of Claude credits. A 5-minute idea. One design doc.

Claude Opus 5.5 worked ~1.5 hours and shipped a playable 3D mobile roguelite: 10 floors, 2 bosses, 12 skills, gear, saves, 3 languages, and a bot that playtests every floor.

Usually the calls are mine. This time I let the agent make them.

What it didn't do: it never ran on a real phone, and balance was tuned only by its own bot tester.

Where it really hits the wall: animation.
Code, systems, menus, 2D art. AI handles all of that well on its own now.
Movement that feels good is another story. Every character here shares one library of stock clips, and the rat is animated by code. My miss: I never pointed it at free mocap libraries.

And magic. I picked a swordsman on purpose. Unique spells and skill effects are exactly where AI still can't deliver, phone or PC. Mocap won't save you there, because it only captures humans.

Next time I test magic head-on, cheaply first, on Roblox.

Finished experiment. Free and open source. Not coming back to it.