Tried the game through Fitgi**
It works! At least on Yuzu, where it is more or less fluid at 30/40 FPS, with cutscenes capped at 30, which seems to be the norm, right?
Riujinx, on the other hand, stutters like crazy, even though Metroid Dread played fine. Perhaps I have to tinker with emulation settings or something.
The game heavily promotes exploration. This will give you glory (resource) and essences which work similarly to how they were in Strange Journey, except applicable to the MC as well. This will give him access to the demons' innate skills as well as resistances. Both the MC and his demons can freely choose skills from them (I haven't had use for the latter feature yet) and the MC gains his resistances this way - you'll essentially have resistances identical to whatever demon you used as base.
So, do the essences influence which skills can you choose during fusion inheritance? Or can you choose which ones to get at will like say the Devil Survivor games? I dunno if I asked this already.