Damn, your graphics were extremely charming and cute, not to mention clean. The gameplay was fun and straightforward, and I got used to it as the levels progressed. The controls were extremely simple yet you have some really well thought out puzzles. Brilliant use of sound effects, and you really amplified the juice of the game. Everything was so well polished and it didn't feel like a jam game at all!
One thing that was mentioned before, the levels did feel slightly repetitive after a while, it would have been cool to see some new mechanics introduced (Though I get that there was a time restriction). Just in case you're planning on expanding on it, which I hope you will since it's super good so far, some new different slimes that have different abilities would be cool.
I absolutely loved this one. Brilliant work!