Hmmm touchpads have a high click delay. Antumbra was not really optimized for touchpads.
It works like this: Every time you click on the angel it gains some "points". You need to get about 10-15 of those points. But at the same time - you loss points of time. So its more about clicking/gaining points faster then the passive loss. If you click like a mad - 5sec of clicking should be enough to do the trick. Tell me did this helped :)
 "Dragons and Titans"){kind=icon}
 "Just Chatting")
 "Cube Escape: Seasons")
 "Dragons of Atlantis")
 "Epic War 4")
 "Antumbra")
 "The Sandbox")
 "Woodclicker")
 "Flight")
 "Soccer Physics")
 "Bloody Fun Day")
 "Jacksmith")
 "Calming Chat 2")
glad to hear :)