I notice while trying to get amulets for more points that building towers reset how many monsters you killed in a row so be sure to build them first and then put all the gems in at once. I know its harder but you need the points for level completion.
 "GemCraft"){kind=icon}
 "Epic War 3"){kind=icon}
 "Cursed Treasure: Don't Touch My Gems!"){kind=icon}
 "Sonny 2"){kind=icon}