I was just wondering, what is so fun about Crysis?

its an open-world-ish kind of game, where you can go about a level the way you want with the help of your nano suit, you can sneak, go all-action and all-guns and kill everybody, or stay back and snipe everybody. its well known for its advanced graphics and physics, and the online multiplayer its pretty good, its not as gory as other m rated games but its still a tad gory.