This is an incredibly creative way to implement shapeshifting into a game. Your wordplay is top notch, but the movement system and form-swapping. Wow! I wouldn't know where to begin programming that.
You make it look so easy to do in the gif, but I couldn't get my humant to ever look quite as human as yours, but I had a lot of fun slamming my ants around the room and up the angles and trying to see what I could come up with.
Lots of places you could take this idea and expand on it. I just love the idea of a group of ants trying to pass themselves off as a human, like three kids stacked on top of each other in a trench coat trying to sneak into a movie.