Infinite lives
SXKAYOVK
Infinite missiles
SZKUANVK
Infinite smoke
VXELTVSE
Start with 2 extra lives
ZEEXKIAA
Start with 6 extra lives
TEEXKIAA
Double missiles on pick-up
TEEXLILA
Slow down timer
YAEZNIYE
Keep special weapons
GXSAKUSE
GXSANUSE