This is a really cool little puzzle game, and a neat take on the theme! The concepts are easy to pick up but there's a rich design space there, and I like what you did with the puzzles. Levels 1-4 were a nice buildup, but I'm still stuck on level 5 (my tiny smooth brain can't figure out how to get Emily over to the left side...). I probably also would have liked for the 2x speed to be the default, or for my choice there to be remembered between levels, since the first thing I did on every level was click that button and it never felt too fast to me.
Very fun game, and I could see it being expanded to more puzzles. Nicely done! :)