A lot of my comments others have mentioned below, but I'm going to just +1 that the tongue was slow, and I didn't know what I could or could not grapple onto. I tried to grapple onto the walls and couldn't. I also tried grappling the platforms and it worked maybe 3/10 times. I lost near the very bottom of the map once because I couldn't get the hang of it.
That being said, the music fit your aesthetic and the art was pretty good :) I think if you improved the mechanics and feel of the game it would be great.
Either way, great job! :D