A mostly functional, slightly stiff platformer. Killing the enemies could have been a lot punchier, a squish or pop or something when they died, as well as giving the player some more feedback when they get hurt. The heartbeat sound works, but some visual/mechanical (knockback) feedback would hammer it home. I also had to restart once as I got wedged in between a skele and the large capy, and couldn't jump my way out.
I love the vibe overall, you'd said you did the art (except the menu background) yourself? I really like it. It's fairly consistent in tone and style, and gives lots of detail for such a low resolution. Great job there.
The story was really short, but that's exactly what you want to do for a game jam: make something short, and then polish it until it's short and sweet. Excellent job on your first published project and first finished jam, thanks for giving us a game to play!