Why is METAL GEAR RISING: REVENGEANCE that cheap?

Simple... it's not a new game. Mortal Kombat and Brutal Legend are good examples of old console games being cheaper than they would have been if they were released for the PC day one. I really hope GTA V follows this trend as well, since it will be 6 months old when it hits the PC.

Also from what I've heard, METAL GEAR RISING is a great game.

It's old o.O? Graphics looks pretty nice to me

Ok the game is not bad it is just at a low price because its been out for almost a year but don't let that change your mind its graphics are still pretty good (don't know for pc played on ps3). Keep this in mind before you buy it, this game is not your normal metal gear stealth, espionage. You are practically not even trying to hide. But don't let that get you down I would say it has some great replay value not to mention that the music in the game is really great. This game does keep with the metal gear timeline though as it takes place after the events of metal gear solid 4 guns of the patriots. overall this is a great game should definitely buy

The reason it is cheap is because it is not MG game, but it labeled as MG, so to make naive people buy this piece of trash they made it pretty cheap.