Not one of the unachieveables, but the secret "The Destroyer" achievement must be at least somewhat glitched. I have played and won over 150 Arcade Mode levels and no achievement. I had heard before it's glitched to some extent, and this must be some proof of that.
50k achieved 10/10/2011
Achievement: Full Recovery(50G) - Alice: Madness Returns
Latest: Puzzle Quest (250)
LEGO Star Wars TCS (760/1000)
Sacred 2 Fallen Angel (930/1000)
GTA V (490/1000)