Cool idea, the slimes look cute. Kinda wished they had colour tho, its kinda hard to tell which is which, even after the fusion has happened.
I dont want to make you feel bad, but the music was kinda frustrating. I get it, its hard to make good music in 48 hours, dont worry about it.
Also I guess it goes without sayingt that this needs some more visuals. Firstly you need to add a way to tell which slime you've selected from the list, secondly, you need to make a way to keep track of all combinations. Sometimes I went into battle with a combination, and lost it on porpuse as fast as I could to try and get another combination. Also, a button to leave levels would be huge!
Still, I really liked the idea, the more I played, the more I was surprised at how much you actually put into the game. Even if its more of the same, you made so much in so little time, and to me thats a win.
Keep at it, you seem really talented at this and I hope to see more of you next year.