[bluGill]

Anybody writing a game should be writing in a game engine. There are too many things you want in a game that just come "free" from an engine that you will spend years writing by hand.

GC can work or not when writing a game engine. However everybody who writes a significant graphical game engine in a GC language learns how to fight the garbage collector - at the very least delaying GC until between frames. Often they treat the game like safety critical: preallocate all buffers so that there is no garbage in the first place (or perhaps minimal garbage). Without garbage collection might technically use more CPU cycles, but in general they are spread out more over time and so more consistent.