Then it must be Game Maker being funky with controllers. I had the same issue with a PS4 pad, which fixed itself in a newer build of Game Maker Studio 2.
Yeah, the full game will have a variety of MP recovery items.
Might just be other controllers conflicting, try unplugging all other controllers. If that's the only controller you have plugged in and it still doesn't work, then I dunno. As a last resort, you can launch the game through Steam and use its built in controller support.
It might just be GameMaker not liking wireless pads. Try updating your controller drivers. If that doesn't work, you can try running the game through Steam, which has its own controller support.
It's not, and it can't happen anywhere else in the game. It's caused by the fact that collision check with the item happens before the game clamps Reisen's position, causing this to happen: you pick up the item -> game pauses -> game moves Reisen away from the item -> games stays frozen and no health is added. This happens because the code for health regeneration is in the item's collision event.
