The game does more for the FPS genre than it gets credit for.
A disclaimer is that I had not played the original Crysis. The game does more for the FPS genre than it gets credit for. While the graphics are its known core competency, the gameplay, story, and replay-ability are its lesser known strengths.
The game leaves you in large open areas, large narrow areas, small open areas, small narrow areas, some busy with obstacles and barriers, some devoid of any tactical items; the levels are plenty varied. The campaigns objectives felt like they added to the story and felt less 'busy work' like some of the campaigns do nowadays. No hitting switches, doing item X to get through a doors, little to no 'aww man bad luck…..this easy objective will take extra long now because freak accident X occurred". You are basically in a state-of-the-art nanosuit and it finally gives justification as to how you can dispel an entire army as a one man team, which most FPS have to suspend your disbelief. There are many ways to complete an objective; stealth, walking juggernaut, etc. The suit can even tell you different ways to complete a mission. The game does a great job of making you feel like you are thrown into a superhuman state in Manhattan.
The story is pretty decent for a FPS; I may even say my favorite since the original Modern Warfare. There are plenty of twists and turns and the plot feels more like an elongated movie than a video game because of the campaign factors I had listed earlier.
You can almost use the same guns the entire game. It gives you freedom to do what you want. There is a decent variety with ones that fuse current tech with future tech that make them look and feel like real guns in the not-so-distant future as well as some oldies but goodies if that's what tickles your fancy.
While everyone will talk about its graphics, the AI is horribly inconsistent. They can see me through walls when I uncloak, be overly intelligent or overly dumb when cloaking and uncloaking. I also noticed a ton of AI bugs where the enemies are stuck or stuck in a routine causing them to spin a mile a minute.
This game gave me the biggest "wow" factor I've had since I first played Combat Evolved, which is saying a lot. The vast pretty environments will tend to do that.