Nightfall Survivors was born in the browser: TypeScript, Canvas and a Node server for co-op. It shipped 27 versions in three months. But the game wanted to go where the browser does not reach well — Steam and phones. So, in October 2026, the move to Unity began.
Parity before beauty
The migration rule was simple and strict: the first Unity version has to play exactly like the web game. No redesigning mechanics along the way.
To get there, the whole simulation was rewritten in pure C#, with no dependency on Unity, in a project that serves both the game and the co-op server. And “exactly” means bit for bit:
- the web game’s random number generator and trigonometry were ported with the same polynomials and the same order of operations;
- JavaScript rounding, which differs from C#, got its own implementation;
- on Android, even the processor’s fused multiply-add was turned off, because it would change the last bit of the math.
The web game became the oracle: a script records, tick by tick, a summary of the state of every test run, and the C# tests point to the first tick where the two versions diverge. Today 15 survival mode scenarios, the Boss Rush bosses and all four Stage Mode stages match bit for bit.
Phase by phase
The migration was split into phases with exit criteria. Foundation, deterministic core, simulation, playable client, visuals and audio, interface and game modes are done. Accounts and the leaderboard, putting co-op online and the stores are still ahead. The roadmap shows each of them with an honest status.
What about the web game?
It is frozen: it is still the reference, but new content — such as Execution and the Void Implosion — is born only in Unity. The classic game page tells the rest.
