This game is the definition of jack of all trades. It does everything but excels at nothing. It still plays very uniquely, though. Expect the campaign to be awful, but if you learn all the hidden mechanics the game doesn't really teach you, it makes mercs a ton of fun.
Rent it first, then decide afterwards if you want to buy it. I do can say that this game is more of a shooter game like COD than a survival horror game like the older RE games. If you were looking for the later, I can recommend instead Resident Evil: Revelations and/or the Dead Space series games.