Ok. I reach the level with the ball, but can't find the solution, will try again later. The mechanic is interesting. The vfx on the sword is awesome. However the combat feels uneven. Sometimes I just kill the skeleton in one slide, and sometimes the sword does not harm them at all.
Another thing: the retry feels sooo slow. The warp effect is cool the first time, but after retrying 5 or more times a level, would love it be able to skip it.
The levels visually simple, but you made a good job with the illumination, making them feel like caves. Good job!
Anyway, I think there's room for improvement to make it a great game.