Maybe I'm picky, but the one thing I can't get past is that the SAM Turrets only shoot the ground creeps...SAM stands for SURFACE TO AIR MISSILE!!! This should be the flyer only weapon.
grab the fuel tank and the level 2 left rocket (or right) and try to get a really awesome day 1 (I restarted 2 or 3 times). i ended up with about 4 grand to level up for day 2. grab some radar fuel tank, left and right rocket and fuel sucker. I made mars on day 2.
 "Crush The Castle 2"){kind=icon}
 "Xeno Tactic"){kind=icon}
 "Hedgehog Launch 2"){kind=icon}