I played the Windows version through to 1-4 and beat the boss, but after defeating the boss, the game doesn't go any further. I have a big donut that was used to kill the boss, but nothing else. I can move the big donut around the screen but can't proceed to the exit....Only can quit the game back to the level select screen, and then I can proceed to the 2-1 level. (so obviously I beat it). Did I miss something to not be able to exit on the level 1-4 here?