I love the idea, it's a unique application of the sliding block puzzle that gets you thinking way more broadly.
The art is excellent; even with a very small character you're supporting, you can still read everything very clearly (and even get a bit of a sense of personality from the little one!)
I'd love to see a speed-up function, as there were a few moments where I had to reset a stage and wait for my character to get back up to where I got to last time.