Personally I think it's fine. However, there are a two things that could change. The first is the light of the player character be unlimited, because if you wait too long it will deplete into a small light. You can alternatively use the summoning ability to reset it for them if you get stuck. The second is the screen freezing when a ghost picks up a human. I honestly don't know if this is intentional or the fault of my PC, because the tutorial is the only way I can see how the ghost plays....

Lol what. Same map, even.

You can find the GitHub repository here: https://github.com/zibetnu/haunting-hijinx

Haunting Hijinx officially supports the Steam Deck. Right now the only known issue is that the on-screen keyboard does not come up automatically. Once that's resolved it should have no trouble being verified.