Haha, fun concept. Though, it gets boring once you get to big. It’s fun to squach huge groups of enemies at once, but only for a bit.
If you decide to work this into a larger game, I think it would be cool if you can use your mass as currency for upgrades.
I also like that killing the enemy doesn’t make you big instantly, but you have to pick up the remains or otherwise the enemy seems to pick it up and grow instead. Atleast, I think that’s what’s happening.