Opinion on 2D games?

I am currently working on a 3D engine (FPS) but that idea has been done to DEATH. I was thinking about how much fun my 2D games were. Worms, etc; What does everyone think about 2D games? If it was a good one, would it be something you all would purchase? Or am i doomed to write the same old rehash of a 3D engine?

its all about playability. fancy 3D graphic engines are appealing but when it comes down to it, its content that really matters. if a 2D game is “fun” then it can sell, if a 3D game suxorz… well i might sell anyway just for looks but in the end it will die out from a highly criticized 5 mins of fame.

i suggest coming up with the game idea first, then deciding if it would be better as a 2D or 3D game.