The main change for PC/Mac is that the 'reveal keys/chest' button no longer has a time limit. The keys are revealed for the duration of that level. You start with two tokens, get another every third level, and if you complete a level without being spotted by a ghost then you get a bonus one! Up to a maximum of 4, above which you get a score bonus instead.
The other background changes are with regards to how cloud saves work, but don't worry your existing settings won't go anywhere. The main changes are the generic cross platform stuff, as the game also supports Android and iOS. Lots of work not applicable to PC/MacOS.
Please let me know how you get on. If you enjoy the game, please give it a thumbs up!
Thanks for playing Embermaze: Descent!
Graeme