At each entrance you want to build one of each turret, Shredder, Laser and SAM. Expand your base quickly and unpack an Emissary at the east entrance so you can build base defences there. Have one Shadow Team go into each once they are deployed. You need to buy yourself some time as the next few minutes are very tough. Set up all four Reckoners at the north entrance. The battlefield now expands and you get reinforcements.
Kill all the infantry and then go for the buildings leaving the Ion Cannon Control Centre until last. Have them both destroy the nearest Power Plant and rush your Commando across. Tell two Shadow Teams to take off and have them land at the southern most point of the central island. Two Watchtowers are preventing you from crossing.