I should start off by saying that I never really play platformers, and I've never been overly fond of them except for a scant few (Oddworld: Abe's Oddysee is the only one I've ever played to completion). So my feedback is from the point of view of someone who isn't part of the target demographic.
The other comments here mentioned the issues with the player characters physics and I encountered several as well, I got stuck to the side of blocks, couldn't fit in some areas, and sometimes got launched into the sky when attempting to jump up the side of a wall.
I also found it difficult to actually attack enemies, with the sword attack I was unable to attack one of the big walking enemies when he was right next to me. With the fireball attack it was hard to hit enemies as I would be too high or too low to attack and trying to attack while jumping seemed unresponsive.
I do like the concept of the character dying and going to hell and then going to back to life or heaven. It's cool how the spot in the level corresponds to the portals as well, kinda reminds me of how they pulled off the Time Warp mansion in Dishonored 2.
As for the art, music, sound effects and animation quality... Well you've seen my game, so I find it kinda charming.
Overall there's a number of technical and possibly some design issues regarding character height, but if those could be resolved then the concept could make for a much better game. Good work!