On each level you can find a rock.  Find it, and shoot it
 until it turns into a dimension door - this is a warp to
 the next level.
 
 -or-
 
 Start with:  STEL7 CHT
 Unlimited lives follow.
 
 -or-
 
 Start with:  STELLAR7 -IAMNOGOODCHEATER
 
 And use these keys in the game:
 
 [F1] Skip levels
 [F2] Full shields
 [F3] All power modules