The series revolves around a group of military protagonists with "nanosuits", technologically advanced suits of armor that give them enhanced physical strength, speed, defense, and cloaking abilities.

The protagonists face off against hostile North Korean soldiers, heavily armed mercenaries, and a race of technologically advanced aliens known as the Ceph, who arrived on Earth millions of years ago and have recently been awakened.

The series consists of three main installments, a standalone spinoff of the first game with a separate multiplayer title, and a compilation.

After arriving on the island, however, Raptor Team's ranks are thinned by mysterious flying creatures, eventually leaving only Nomad, Psycho, and Prophet, who is subsequently kidnapped by the organisms later called the Ceph.

Nomad, Psycho, and Helena escape and receive a distress signal from the still-alive Prophet, and decide to return to the island.

After numerous setbacks and the assistance of his friend O'Neill, Psycho successfully defeats Lee, obtains the alien, and brings it back to the carrier fleet.

A sequel set 3 years after the first game, Crysis 2 takes place in New York City in 2023, which is infected by an unknown virus.

Alcatraz and Gould team up with Tara Strickland, an undercover CIA lieutenant, and Jacob Hargreave, the original creator of the nanosuit.

The game closes with Alcatraz being contacted by Karl Rasch, a nanosuit scientist, and vowing to continue the war against the Ceph.

Set in 2047, the game sees Prophet return to the now nanodome-encased New York City, on a mission of revenge against CELL, having uncovered the truth behind their motives for building the quarantined nanodomes.

"[28] GameSpy gave it a 4.5 out of 5 stating that the suit powers were fun but also criticizing the multiplayer portion of the game for not having a team deathmatch.

[29] X-Play gave it a 3 out of 5 on its "Holiday Buyer's Guide" special episode, praising the graphics and physics, but criticized the steep hardware requirements as well as stating that the game is overhyped with average gameplay.

[30] GamePro honored Crysis with a score of 4.75 out of 5, saying it was "a great step forward for PC gaming", but criticized the steep hardware requirements.

The phrase has continued in modern usage, as a snowclone, with any other high-end (or ironically low-end) game title replacing Crysis.

Indeed, some reviewers did not see any significant performance improvement with Warhead compared with Crysis, stating that only high-end GPUs could handle the game comfortably at decent frame rates.