It really depends on the game. If the game was truly native, usually the Rosetta performance is good. A lot of games though are JIT, and running a JIT inside a JIT is terrible for performance. The good news is that a game already being JIT is probably easier to patch to be native, for example people have had success replacing the mono runtime used by terraria with a native one and seeing good performance improvements, or running Minecraft on a native JVM. The bad news is it doesn’t necessarily mean the developers will actually update the thing, and mods like this are unlikely to appeal to the vast majority of people.
It really depends on the game. If the game was truly native, usually the Rosetta performance is good. A lot of games though are JIT, and running a JIT inside a JIT is terrible for performance. The good news is that a game already being JIT is probably easier to patch to be native, for example people have had success replacing the mono runtime used by terraria with a native one and seeing good performance improvements, or running Minecraft on a native JVM. The bad news is it doesn’t necessarily mean the developers will actually update the thing, and mods like this are unlikely to appeal to the vast majority of people.