The Mech Suit is first featured when Kinzie introduces The Protagonist to it as "Power Armour" when they have to rescue Matt Miller. They disapprove, and continuously, throughout the game, call it a "Robot". Keith David also refers to it as "Power Armor", but Matt also calls it a "Robot" like The Protagonist and makes them rant about how Kinzie is wrong, even though she continues to disagree with them. Initially, it is not equipped with weaponry, and only melee attacks are possible, however later, Matt equips it with a minigun and rocket launcher. The Mech Suit is capable of melee attacks and hovering. The Mech Suit is later on unlocked for use in The Simulation.
The Mech Suit is able to body slam, ground slam, and smash enemies with its powerful arms. With its arsenal of rocket launchers and handy miniguns, it is unstoppable in the face of all but the strongest foes.
- The Mech Suit was first revealed in the PAX gameplay video.
- The Health drops of the Mech Suit look similar to Salvage in Red Faction: Armageddon.
- It is not possible to recruit or dismiss Homies while in the Mech Suit, although Homies called via the Cellphone are added to a Homie slot.
- When Smoked while using the Mech Suit, The Protagonist respawns with it near the closest hospital, but only melee attacks are available. Health and fuel are not displayed. This is fixed in updated versions.[which?]
- Calling Mech Suit Delivery inside of buildings enables Mech Suit's weapons but it doesn't appear and Super Powers and weapons are not available.
- Switching to another weapon "drops" Mech Suit. After being dropped, it cannot be picked up again.
- Zinyak uses his own variant of the Mech Suit against The Protagonist.
- It is possible to bypass the barrier above The Simulation.
- When hit by a Suppression Grenade while in a Mech Suit, it descends much slower.
- The Mech Suit has whatever Health The Protagonist currently has.
- In PAX Demo, the Mech Suit is a bit slower and features different HUD, similar to The Ship's in "The Real World" and "Pop his Top".
- The Mech Suit might be inspired by the SOP-MA1 Battle Armor from Red Faction II. Both the Mech Suit and the Battle Armor have similarities in their weapons configuration (miniguns on their arms and rocket launchers on their shoulders) and have a temporary use through both games.
- The Mech Suit is entirely cabable of single-handedly going from no notoriety to beating a Warden (however it cannot initiate the final move)
- The Mech Suit is a weapon rather than a vehicle, and can do things like collect clusters, breaking a Warden's shield with rockets or a slam, and telekinesis cannot be used on it.