The suits abilities in Crysis are essentially cheat codes and the developers made them into gameplay elements. I would classify that as a gimmick, but a damn good one. I read developer interviews where the suit wasn't intended as an essential part of the gameplay at all until the very end. Later the in the development cycle they thought it would be cool to have the entire game revolve around that. I'm not knocking Crysis at all btw, besides that I would have to acquire a supercomputer from the future to run the damn thing at an acceptable level.