Quite addictive! Freezing and then pushing the enemies into each other was pretty satisfying, in particular.
The last part of the boss is unfortunately pretty trivial by simply not moving much and grazing the big, red spear bullets. Since the line of smaller red/blue bullets just spawn around you at a relatively non-threatening distance. Comparatively the previous pattern with the rainbow bullets was much trickier.
Since this game doesn't have voice acting (which is obviously fine), it's probably better that the game pause when there's dialogue. The text was also a bit difficult to read since it's not in some kind of text box.
I also ran into some issues where the boss music would stop/not play.