excellent concept, less than excellent execution. The menu music and the level completion music is jarring and out of place after playing the levels; I would rather just have no music at all there. Right-click to delete: it normally took me 3-5 times trying to delete a line before it would actually delete! getting it to recognize the line made the game more frustrating than it needed to be. There are also quite a few bugs in the individual levels. Fix these things, and you could easily have a 5/5 game, but as it stands, 3/5.
Sometimes it prevents me from moving rings that I need to move, obviously the order the rings are sent out in is random, because I've sometimes been forced to put a green ring on a yellow ring because there was no possible way that I could move any of the rings. It's one of the easiest games I've ever played, the only challenges are the glitches. 2/5
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 "Monkey GO Happy"){kind=icon}
 "Achievement Unlocked"){kind=icon}
 "Monoliths Mario World 2"){kind=icon}
 "Rings"){kind=icon}