Really interesting metroidvania concept!
It was pretty fun once I got the hang of it, but there's a few small things that make the game a bit difficult. First, once you completely lose the jump ability you're basically helpless until the loop ends. Either making the level 1 jump something you always have or redesigning the world so that it's always possible to backtrack would go a long way to removing some of the frustration of waiting ~20 seconds just to get your jump back. Second, on a few loops I lost a ton of abilities, and it was a bit of a slog to get them back, mostly because I wasn't entirely sure which abilities I lost and where they went. I feel like collected abilities should be indicated with some UI element so they're easier to find again. Finally, the attack speed should be increased a bit to make fighting enemies a little easier, especially since the cost of getting hit by them is so high.