Took me few attempts to beat first karen, since im not that good in bullet hell games. Difficulty is quite brutal before you get upgrades :D
Maybe white bullets with bright background wasn't the best contrast in some of the levels. Also in one of the section there was some kind of structure in background that had same color as ship, so i kinda lost sight were i even was. During one of the boss fights dialog boxes got in the way of enemy projectiles.
Having C button to return back to starting menu might not be good idea. I feel like player could press it by accident.