The characters are fun and I would like to see more of them. But I have to say the prototype is rough, not because of the art but just the way that the levels aren't built on any sort of grid, it's just one of those things that make puzzle games more difficult to read and especially easy to be misread.
It's clear that there's a lot of care and love put into the idea and the characters, I'd love to see them given the time for them to really come into their own.