FPA: World 2 Perfect.
This game is incredible, simply put. The actual amount of charm that has been worked into this game is unbelievable. Apart from the amazing level design, perfect humor, and funny little quirks(like tapping down to make him headbang). This game contains something that most others just can't produce: Fun.
FPA:W2 doesn't rely on mind-numbing difficulty or overworked graphics to be good. It's good because it's amazing, doesn't lose its charm, and is simply fun to play.
The physics used for running, sliding, climbing and wall jumping are amazing, and should become a benchmark for platformers.
Also, Idle animation=win.