That was very fun. I could see this mechanic being put into a full-size bullet hell.
It was just simple enough to be easy to pick up but ramped at the correct pace
I would've liked to see a different way of differentiating the enemy types. Perhaps different colours or shading? I did find that the subtle size difference wasn't quite enough. On the other hand though, perhaps not being sure how an enemy was going to behave was part of the challenge.
Thanks for creating!