Fun
Enjoyable, but I had a number of issues super early. Audio had a lot of problems, and when I landed on wall spikes the corpse would float above it. Once I figured out the corpses just weirdly float, I was able to figure out how the puzzles worked.
Great checkpoint system.
Aesthetics
10/10. Great color choice. Pixel art looks great. Love the little landing clouds and death animations.
Music
Very good music. Fits the game.
Sound
Great use of sound, and it is picked very well. Bugged though. Wish it didn't crackle constantly.
Mechanics
Using the corpses of your previous lives is great. I've seen a few times in this game jam, so it mostly comes down to implementation. I encountered a few bugs with where the corpses landed and their hitboxes, but otherwise good use. Having the corpse stay floating mid air rather than fall to the ground is an interesting design choice, but it worked really well and lent to some interesting puzzles even if it looked bizarre.
The movement is solid. Good speed and jump acceleration. No complaints.
Story
Seems the story is to get out of the catacomb? Didn't find anything regarding story outside of conjecture.
Theme
10/10 here as well. The mechanic fits the game jam theme perfectly, and you used the nine lives of a cat to further explain the multiple lives mechanic. Art, music, and sounds all come together and work in harmony.