It's a shame this was dismissed by some people as being nothing but a glorified tech demo, because the gameplay is actually something special. The suit powers are a lot of fun. You can use the cloak ability to go invisible and stalk an enemy like the Predator, then switch to strength mode to grab him and throw him off a cliff. Swiftly escape the rest of them with the super speed ability, and then switch back to cloak mode and watch them run around panicking. The huge open-ended environments nudge you ahead on a set path, but allow you to approach situations in your own way, and the smaller buildings are fully destructible. Combine all these things together, and you have some of the most emergent gameplay you'll ever see in a first person shooter. Each encounter plays out differently than the last one, as long as you're willing to experiment. A lot of the best moments happen unexpectedly and are completely unscripted, when all of the different mechanics just come together in a spectacular way. It was even more impressive at the time of release, simply because of how ridiculously gorgeous it was. Crysis was so far ahead of its time graphically that it's hard to even put into words. I'm glad to report that it still looks quite nice today, and some things are actually still impressive, like the way that trees can get cut down by gunfire. It will still push your system a little too, but I think that's more due to poor optimisation than anything.
I have two main criticisms to start with. Firstly, AI is not the game's strong suit. Enemies are utterly thick one minute, not even noticing me while I'm pelting them with bullets, and hyper-aware the next minute, spotting me while I'm hidden in bushes a mile away. It's very inconsistent, and I'd prefer something in-between these two extremes that just doesn't exist in Crysis. Secondly, the suit energy levels are too limited, and it can sometimes feel restrictive, like the game is holding me back from experimenting. I know the game would be easier if we could use our powers more, but there are other ways they could have balanced the difficulty and maintained a challenge. I decided to make some of my own tweaks to the suit energy in a CFG file, and to compensate for that I increased the enemies' difficulty and health. I found the game to be more enjoyable with my own tweaks than without.
So far these are just small criticisms though, and for around two-thirds of the game, everything is great. But then you get to the "Core" level, and it all goes to shit. Core is the worst chapter in the game; a dark zero gravity environment with a confusing layout that makes it very hard to navigate. You're fighting the aliens for the first time, who move quickly, are hard to hit, and take too long to die. They just aren't fun to fight against at all. When you finally get out of the core, you might breath a sigh of relief thinking everything will return to normal, but no. You'll be spending three more hours fighting the same annoying aliens in a different skin, and the gameplay turns completely generic. The level design starts pushing you down a one-way path, relying on set pieces rather than interesting unscripted encounters. Only one of your suit powers is any use against the aliens, which is cloak, and that's only to confuse them for a moment or escape if you're surrounded. So it felt like everything the game had taught me up until that moment was suddenly pointless.
The last part of the game isn't good, and might leave a bad taste, but the rest of the game is very fun and unique.