Classified: The Sentinel Crisis is a budget-priced first-person shooter that takes place in a futuristic setting. You play as a mutant super-soldier resembling Master Chief, wearing the military's new "Sentinel" suit that makes him stronger, auto-heals him, and targets enemies. A group of terrorists have managed to find out about the Sentinel suits, and have kidnapped a scientist that helped develop the suits. You must destroy the terrorists and make sure that the Sentinel technology does not fall into the wrong hands.

As with many other budget-priced shooters on the market, the gameplay in Classified: The Sentinel Crisis is very similar to that of the Halo games. Most notably, the auto-healing system is similar to Halo's "shields" system.