The first thing that stood out was definitely how long the turns took. The enemy turn needs to be much quicker, especially at the end when there are fewer.
My first play I lost with, I think, 4 left. The second time I beat all the enemies I could, though did not get any kind of game over screen. I did notice what looked like it could be the leg of an enemy at the top left of the screen, as if one had spawned outside of the play area and could not move or be reached. This was on a second play after losing, so it may be tied to that.
The base gameplay works pretty well, other than the slowness of course. I like that you have 2 enemy types with one being melee and the other ranged. I had not acknowledged that at first, though did see some looked a bit different. It was only on the second play that it clicked what the difference meant, and I was able to use that to do better, though still lost 2 hearts.
Overall, a decent puzzle game for a jam.