Something to note - this game doesn't run on a CPU with more than a certain number of logical processors (I think it's 16). The only solution seems to be using a batch file to launch the game with CPU affinity set to use only 4 logical processors, though YMMV. For me (using a Ryzen 7 3700X), the Steam version refused to launch at all, but the GOG version did work using the aforementioned affinity trick.
Topic on Talk:Blades of Time
Discovered a more permanent and less janky fix, edited the page to reflect.