I like the idea a lot! Slingshotting is pretty fun as a mechanic, but in this case I think you may be demanding a bit too much precision from the player. It took a lot of tries just to get past the second level, and I got stuck on the fourth with the super narrow platforms. I'm not sure what the answer to this one is exactly, but I definitely needed a bit more flexibility in the aiming. It also would have been super helpful to see a hint over which character you're currently flinging, as a few times I accidentally shot the wrong character.