2009 · Puzzle
Levels of Bloons specifically chosen to be super-tough to beat.
2012 · Android, Windows +1
2013 · Android, iOS
2010 · Browser
2012 · Android, Windows +2
2010 · Nintendo DS
2011 · Browser, Android +1
King
2009 · Wii
Added from the IGDB catalog; not on any collection yet.