Action-adventure Game Prototype, created by Radical Entertainment and published by Activision, is typeset as [PROTOTYPE].

The Game's setting is New York City, where a virus is spreading, and the military is attempting to stop it. Alex Mercer, the story's protagonist, has the power to shapeshift and absorb enemies.

Memory, experiences, biomass, and physical forms of foes eaten by Mercer can all be retained. Additionally, Alex can transform specific body parts into more advanced types of weapons for both offence and defence. These are all meant to work together to allow players a variety of approaches to accomplish their goals.

Gameplay:

Among Alex's improved parkour skills are the ability to run up the sides of buildings, jump hundreds of metres, glide through the air, and sprint at breakneck speed eternally. No matter how high they are, falls do not hurt the player, but higher ones will distort the earth. In addition to performing melee attacks without using shapeshifting, Alex is also capable of using a variety of weapons, capturing and controlling military vehicles, including helicopters, and serving more gymnastic moves like air combos, sliding along the ground while using any human opponent's body, and a fast-moving cannonball attack. Although Alex may recover to a limited extent outside of battle over time, he can regain health by devouring biomass.

Alex's major superpower is his ability to shapeshift, which allows him to change various portions of his body into a variety of martial arts weapons that he has earned throughout the Game, either as paid upgrades or gifts. The enormous, strong Blade, swift, razor-sharp Claws (which can also shoot large spikes from the ground), the telescoping Whipfist, Muscle mass, which increases his strength, and large, club-like Hammerfists are some of his offensive abilities.

In terms of defence, Alex has two options: a sizable shield that must heal after a lot of damage and a full-body armour that trades agility and speed for overwhelming toughness. When both are equipped, Alex can quickly go past most barriers. Thermal and Infected are two vision modes that let Alex see opponents through smoke and other obstructions. Any combination of one defensive and one attacking power each may be used, but doing so will make Alex visible and remove any disguises that may be worn.

The Devastators are the most potent assaults, and to use them, Alex must be in Critical Mass, which can be defined as being close to death or having too much-stored biomass. These include the Critical Pain, which fires a single beam of hardened biomass from his hands to deal damage to a single target, the Groundspike Graveyard, which erupts gigantic spikes from the ground all around Alex and the Tendril Barrage, which impales tendrils from his body in all directions.

Sequel:

Sometime in December 2010, Radical Entertainment unveiled the "Murder Your Maker" teaser trailer. The game now centres on Sgt. James Heller is a veteran who returns to the city that has been devastated by war.