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Unity games always seem to have memory leaks. I'm not sure if it's the engine or the game.

If I use ulimit to set a memory limit, the games behave. Otherwise, they'll keep sucking of memory till my computer crashes.

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Isn't that just how the C# garbage collector works?

Not really, there is a big difference in how Unity and CoreCLR GCs work. CoreCLR itself has two-ish GC implementations that are very differently tuned (WKS GC and SRV GC aka Workstation and Server). This is further complicated by DATAS mode, if we talk about implementation, as it dynamically scales heap count and sizes based on application allocation behavior, time spent in GC and the proportion of memory used (enabled by default in .NET 9 for SRV).

AFAIK Unity uses Boehm GC based implementation with augmentations for incremental per-frame collection. It can sustain much, much lower allocation throughput than what CoreCLR uses (and CoreLib APIs try to be not allocatey as well). Would be interesting to read more if someone with better Unity knowledge chimes in.

There's a pretty good memory profiler for it now that can find and fix this. It's possible to leak memory in any game engine.

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