Firepower 2000
   

Drive both vehicles
Hidden Bullet tokens
Warp


Drive both vehicles
During the Title Screen, push Select. When the two-player option is
displayed, press Start and A simultaneously. You'll start a one-player 
game, but you'll be able to drive both vehicles.


Hidden Bullet tokens
At the beginning of Level 1, steer to the far right to find a yellow
container. Blast it open and collect the Bullet tokens to power up. 


Warp
While playing the game, press Start to pause. You can use the 
following codes (with the L and R buttons) to jump ahead one Level 
at a time. You can use these codes consecutively to go from Level 1 
to Level 6.

Lv. 1 to Lv. 2: R, L, R, R, L, L, R, L, R, R, L, L 
Lv. 2 to Lv. 3: R, L, R, R, L, L, R, R, R, L, R, R 
Lv. 3 to Lv. 4: L, R, L, L, R, R, L, L, L, L, R, R, R, L 
Lv. 4 to Lv. 5: R, R, R, L, L, L, R, R, L, L, R, L, R, L 
Lv. 5 to Lv. 6: R, L, R, L, L, L, R, R, L, L, R, L, R, L, L