This is really neat! This style of game isn't really my usual thing (I don't have a very good sense of timing) but the puzzle aspect was fresh to me and kept me trying until progression required maneuvering past a whole bunch of slimes.
lol, yeah thats a hard part, if you do wish to come back, try setting the solid size to small, and then holding down the left arrow key to get past the first one. After that you are on your own