From the team that brought you Aleph One, the classic sci-fi FPS Marathon from Bungie on Mac revived for modern hardware and maintained by the fan community.
I think the big challenge with modernizing it for a new engine is the invalidity to jump (except the grenade jump, of course). A few notable puzzles built around getting around the long way to the top of a a 3’ ledge
You don't need to change anything other than the graphics and do some quality of life changes and additions. There's no reason at all to add jump if the original doesn't have it.
Modern hardware is fast enough that anything that's too old to run directly is (usually) also no so demanding as to be a problem under full virtualization.
Yeah, I guess I'll end up doing that. I managed to get some other old games going under various versions of Proton or vanilla Wine but Myth seems really finicky. WinXP VM it is, I guess!