Fun idea! I can see a few interesting puzzles you could come up with what you have here.
I have a few things i'd like to mention though. I think the background was a little too noisy and that made it hard to focus on the character itself. Now i'm no expert, but i believe one way to fix this is by making all the background colors closer to the same color. That's what i'd do at least, but like i said, im no expert so i have no clue what i'm talking about.
Another thing is that the slimes didn't give the player any feedback. Maybe add some shooty shooty sounds, maybe a hit flash and screenshake to make killing slimes more like a fun thing to do than just an annoyance i jumped over. I also think they had a little too much health.
With a little more tweaking, i think this'd be a really fun puzzle platformer. Overall really nice for a 7 day game! Good work!