Game Vanished!

[Alice G]

Hello,
I need some help because a couple of days ago when I clicked on the game's icon in my hard drive to open the game, it did the initial loading bar screen and then that went away and nothing else happened. Then the game's icon completely vanished! I can't find it anywhere! I've searched my mac completely and I'm pretty sure it's gone.
Does anyone know where it might be?! I didn't think apps could vanish like that!

Should I just download the game again from the mac site like I did in the first place? Would that mean that I'd lose my account and have to start at level one again? (I think I'd give up!!)
If anyone knows what to do then I'd be v. gratefull!!