As you enter Beast Wars, a Maximal ship has chased a Predacon vessel through a time warp, and both have crash landed on a planet much like Earth in the time when the dinosaurs ruled. On landing, the Predacons steal a golden disk containing the location of a major Energon source which, if found, will enable them to resume an intergalactic war with the Maximals.

The Maximals and Predacons realize the power of the Energon is so intense it will damage their robotic structures with prolonged exposure. Therefore, to survive in this environment, both groups use biogenetic engineering to fuse their robotic body structures with native animal life forms. The result: wild animals that can transform into robot warriors to engage in an explosive fight to the finish. (description available courtesy of psxa2z.com)

CHEATS

Weapon power-up:
Pause game play, then hold L2 and quickly press Up, Down, Left, Right, Triangle, X, Square. Release L2, then immediately press Start to resume game play.

Level skip:
Pause game play, then hold L2 and quickly press Up, Down, Left, Right, Triangle, X(2), Triangle, Right, Left, Down, Up. Release L2, then immediately press Start to resume game play.

Ravage:
Select versus mode then choose either human or CPU and hold X. Keep X held and quickly hold L1 + L2 + R1 + R2 + Down to unlock Ravage.

Blackarachnia:
Select versus mode then choose either human or CPU and hold X. Keep X held and quickly hold L1 + L2 + R1 + R2 + Left to unlock the Transmetal version of Balckarachnia.

Windrazor:
Select versus mode then choose either human or CPU and hold X. Keep X held and quickly hold L1 + L2 + R1 + R2 + Right to unlock the 1999 Botcon version of Windrazor.

Tigatron:
Select versus mode then choose either human or CPU and hold X. Keep X held and quickly hold L1 + L2 + R1 + R2 + Up to unlock Tigatron.

Here's 5 minute video from the Beast Wars Transformers TV series (Feral Scream):