Building a Mobile Idle Game in Rust/Bevy Without a Game Engine Background
The line appeared one night and wouldn’t leave:
The station has been here longer than you. It should have been consumed. It has not been. You don’t know why.
I didn’t know what kind of game it belonged to. I spent months carrying it before I found out.
VoidDrift is a mobile idle game where you mine asteroid debris at the edge of a black hole. You build a drone fleet. Factions you don’t understand start sending messages. There’s no win condition. The horizon is a one-way membrane.
I had no game engine background when I started. I’d built systems — ECS architectures in Python, simulation loops, procedural generators — but I’d never shipped a game. I picked Rust and Bevy because the pipeline I needed (Android and WASM from a single codebase) pointed there. The ECS paradigm took time to click. My first systems were monolithic messes that tried to own too much.
The breakthrough wasn’t a technical insight. It was administrative discipline.
I forced myself to write an ADR — an Architecture Decision Record — before touching any major decision. ADR-003: bevy_egui for all HUD because Mali GPU stabilization on Android required it. ADR-007: system partitioning because Bevy’s scheduler hits a 20-tuple limit faster than you expect. Every constraint that would have sent me into a three-day refactor got documented before it became one.
Bevy 0.15 with bevy_egui 0.33 has a specific problem nobody warns you about: egui::Window click events are broken in the Update schedule. The fix is painter + ui.interact(). I know that because I hit the wall, diagnosed it, and wrote it down. The ADR system means I don’t rediscover the same walls twice.
What didn’t work: scope. I wanted branching faction storylines, a full three-ring resource economy, Mk II drone tiers, a complete Human-versus-Signal narrative arc. None of that is in the current version. What shipped is a focused mining loop, a production tree, and enough faction voice to suggest something larger without explaining it.
The unexplained parts are intentional now. They weren’t when I started.
VoidDrift is live on itch.io — Android and WASM from the same codebase. 505 views, 10.4K impressions. A small audience that keeps coming back.
The Play Store is three assets away. An app icon, a feature graphic, two screenshots. Not a code problem. An afternoon problem I haven’t made time for yet.
The station is still there. The factions are still watching. The black hole is still waiting.
Some games tell you everything. VoidDrift tells you enough to make you wonder about the rest. That constraint — deliberate incompleteness — turned out to be the best decision I didn’t plan to make.