I said I should, not I would. For those of you who don't get the joke (probably everyone reading this) both the UFO and the mouse are characters are from the game Undefined Fantastic Object (UFO, 12th game in the Touhou series). Whenever you reach a midboss, any UFO that may be on the screen will fly off screen before their timer runs out (which is a bad thing). If you reach a boss, any UFO that may be on the screen will immediately burst, granting you the treasures inside (which is a good thing). Of course, now that I've explained it, it's not funny. Unless you understood the joke in the first place, of course.