The game uses a fully polygonal fighting engine, with 8 different fighters, and 2 boss fighters.
Bio F.R.E.A.K.S. uses a mix of hand-to-hand and long range combat. Each character has an assortment of special attacks, both close and long range, as well as "finishing attacks". Much like the Fatalities of the Mortal Kombat games, these moves can execute the player's opponents while some, like in Time Killers, will remove limbs. Also damage from powerful attacks can add up causing a limb to be destroyed as well.
The game takes place in 3D fighting arenas. Emphasis was placed on mobility giving dashes a great range and in multiple directions.
The face buttons are assigned to specific limbs. The shoulder buttons are used for dodging, flying, and basic long range attacks.