On the screen allowing you to choose the number of players, press and hold [L]+[R]+L, then press START. You will now be able to play Cyberscape as well as Cyberzone!
On the starting level selection screen, press and hold CNTRL I: [L]+[R] and then press START.
In areas with Gremlins or Yellow Smiloids, a Pod Drone will appear each time you touch a low-level enemy. Shoot the flashing Pod Drones for armor, coins, and Power-Ups.