I love this game: Heres a tactic
My score is 70,905 : Brigadier General
There is a special tactic in this game. It is called Flak.
You upgrade flak and the shield generator buildings 1 by 1, and then you just keep the flak supplied. It will kill most missles :)
When everything fails, I try and keep the shield generator up to sustain the flak for its last attempts to destroy as many missles as possible.. and then when the flak and shields fail I let the enemy take all the other buildings and use my one and only base to fight to the last minute, surviving for another 10 minutes or so...
And finally, when they send dozens and dozens of those green missle launchers.... I finally get overwhelmed, my shields go down, my missles are all on reload, and my energy supply is low - everyone in my base panics and prays on their last minutes of their lives... until finally the base has been destroyed.
In the end, I get many platinum medals, 2 gold medals, and the rank of General!