Very neat concept! It's very creative with how creating huge footprints in turn create new openings for you to reach new destinations.
However, a few nitpickers: I'm not too much a fan of Kalena's monologues that randomly occur when you go huge, it can kinda be a little distracting when you're trying to plan a route.
It's also a bit inconsistent with how the footprint sizes seem to stretch further depending on how you enter certain tiles, so the only real way to be sure how the footprints are going to end up is to use the 'X' button on every single tiles of the map and keep a note to yourself which tiles have a directional limitation implanted, which makes it overall a little tedious.
I think a free-cam mode during your "normal size" would really benefit with the process of planning your path.
Nevertheless, quite a fun and unique experience, it really makes good use of the "size-changing power" I haven't seen that often in games.