README
Rendered from the repository.
A browser-based survivor game with 173 champions, deterministic simulation, and online co-op. Read the full README on GitHub.
Builds / Rift Survivors
Rift Survivors
A browser survivor game with 173 League-inspired champions, deterministic simulation, and online co-op.
173champions
5packages
30Hz simulation
179tests passing
What it changed
What building it taught me.
It started as a survivor clone and became the project where I had to make architecture, performance, and multiplayer work together.
Separate the game from the engine.
The simulation is a pure TypeScript package with no DOM, network, or clock. Content, client, server, and shared protocol sit around it. That split made the same simulation run in a browser worker and a Node server, and it made tests possible without a renderer.
Make the run reproducible before making it pretty.
The game runs at a fixed 30 Hz with a seeded RNG, pooled struct-of-arrays stores, and a spatial hash. Deterministic snapshots let me test the same seed twice, add a headless balance bot, and reason about networking without guessing.
Design for the horde.
Hundreds of enemies and projectiles forced me to avoid per-frame allocations, reuse entity slots, cap pools, and rebuild a coarse flow field every 12 ticks instead of running pathfinding for every enemy. I learned to measure the simulation, not just the frame rate.
Treat disconnects as a normal state.
The co-op server is authoritative, sends full and delta snapshots, and the client interpolates between ticks. Reconnect, resync, bad messages, and a dropped player all had to be handled explicitly. It changed how I think about state that is shared by several clients.
Move the roster out of the code.
173 champions, upgrades, enemies, and stages are typed data validated at startup. Rulesets select systems, registries resolve behaviours by id, and save files have versioned migrations. Adding a champion no longer means editing the tick loop.
Keep the whole workspace green.
TypeScript strict mode, Biome, a CI workflow, and 179 passing tests made the larger changes possible. The documentation, ADRs, and handoff notes were part of the engineering, not cleanup after it.
Still open
The next pass.
The browser build is moving to rift.carletti.work. Matchmaking is not set up yet, unique moves still cover the original eight champions, and co-op needs more human playtesting.