In there is a wide ramp buy about 8 cobras and 20 morters and 20 AAtroopers and line them up at the top of the ramp (your base!) with the infantry in between the cobras. Deploy the cobras & morters and they wont be able to get in! If there is a small ramp use 2 cobras, 10 morters and 10 AA troopers! Anything coming in will be Dead* (*but if they send Ikvines or Minotaurs have about 5 laser tanks charge out and keep moving them until the Minotaur/Ikvine is toast)