Some people use it as a game, but that doesn't make it a game. It's used to train actual pilots.
It's all a mixed opinion. I'd say it's a game, the only real way to learn how do do something is to go and actually do it.
I've been playing FSX for awhile by now, and to be honest, it's more of a game than a sim. If you want a sim, go for X-Plane or something else.
Oh, I almost forgot! I might get it, might not get it. When I heard it's gonna have Honolulu and just 2 or 3 planes ruined it.