This is the first bullet hell game I have played from this jam. I like the interpretation of the concept!
Though I think that there are two things that could up the game to a higher level. First off, tighter hit boxes. It is fine that the single ship grows, but the bigger it becomes the more the hitbox feels disjointed from the graphics, right when you need accuracy the most. Secondly, a reason to split up. Not just change to the two ships, but actually have a reason to not just bunch them up in a way where you still only have 1 "entity" that you control just represented by two ships. Maybe a stunning force field between the two or something might help.