Continue game play:-  Press Start on controller two as immediately after your last ship explodes to continue game play. Then, have player two quit the game and player one will be able to continue.

Extra credits:-  When you finish escorting a ship to its destination, stay with it after you are paid. The ship and the others will destroy enemies for you, leaving credits behind. At times, you can receive 200 to 300 credits before returning home.

Infinite Lives Glitch:-  After dying the 3rd time (when you're about to get a game over) and right after your ship blows up, press Start on another controller and join in with a new character. Your first character will come back to life. Then just quit with the second character, and keep playing until you die again. 

Starbase Locations

Allied: x:-78 y:99 
Terran: x:-3408 y:2400 
Nomad: x:2421 y:14343 
Eldred: x:13652 y:-5886 
Scarab: x:-128 y:-9822 
Drakken: x:12421 y:7476 
Vorgan: x:-12989 y:-5788 
Secret base: x:-17650 y:-16500 
Secret base: x:12340 y:14280 
Drakken Gas Mine: x:22460 y:6180 
Nomad secret base: x:-27250 y:30780

Planet Locations

Desert Planet: x:-22998 y:-5327 
Life World: x:-9330 y:6260 
Ice Planet: x:-14721 y:-20311 
Dead Planet: x:8710 y:-18060 
Gas Planet: x:27421 y:3284 
Volcanic Planet: x:22421 y:24511 
Infested Planet: x:-31250 y:34280

Gameshark Codes

Quick Level Gain A9EB633D00000090
Infinite Power Pods 90F8385B00000003
Infinite Credits E9AF2A3800000090