Ironically, I used this same tileset when I was working through the CS50 game development course (Zelda lecture).  Good memories!

The tip on K below helped.  The animation is a little long on that.  For trapping slimes, players might want to do that a little quicker.  Especially if a slime is already chasing them.  Maybe just after the first animation?  Just my opinion, of course.

Over all a fun little game.  Nice work!

I got stuck on the 3rd level when you go around the perimeter. The timing was difficult and it didn't seem to line up with the pink slime's timing of getting out of its trap. Really well made though! Great work!