(For a description of this creation as in The Dreadnought Contingency universe, click [here].)
While Antigravity looked generally better in my opinion than its predecessor, Gravity, whose legs were reused for this build, I didn't like it quite as much. I'm not entirely sure why, but it's likely because Antigravity lacked Gravity's defining trait: a strikingly large and diverse array of weaponry. It was by no means unarmed, however, possessing the same leg-mounted rockets as Gravity, two dual anti-infantry machine guns, two different kinds of missiles with an individual total of 14, and Ironman-style thrusters with the ability to destroy practically anything nearby in a flaming whirlwind of death.
As its name would suggest, Antigravity is capable of sustained flight. This is accomplished using its three main thrusters, but also in part by the two gravity engines on opposite sides of its back. To have sustained flight require less thrust, the Antigravity uses gravity dilution to lessen the intensity of the earth's pull on itself. Likewise, to stay stationary while using its thrusters as weapons, Antigraity utilizes gravity generation, effectively making itself heavier that it normally is. Antigravity can also use gravity dilution for jumping great heights and distances, meaning flight is not necessary for simple obstacle overcome.
Besides being the only flying mech I've ever made, Antigravity is also unique because it's primarily an odd number of studs long. This was probably done to make integration with the Technic waist that was re-purposed from Gravity easier.