Got my first achievement Jan. 16, 2012 and now finished the Dec. 04, 2014. Hell of a game perhaps the best TD ever made. Also on the last level, orange crystal is important. Had 3 traps with orange gems and then the mana just rolled in. Tried it like 5-6 times with different strats but this was the winning one.
 "Christmas cat"){kind=icon}
 "GemCraft chapter 0"){kind=icon}
 "AdVenture Capitalist"){kind=icon}
 "Resort Empire"){kind=icon}
 "Theme Hotel"){kind=icon}