There should be a help page somewhere in the game where it shows you what to do and what the buildings are for. Also how to win the game and all that stuff.
Best weapons you need to use to beat the last missions of the alien campaign: HOLY GRAIL (extremely powerful and accurate) and the ROCKET LAUNCHER.
DON'T BUY ANY OTHER ROCKET LAUNCHERS, THE ONE YOU START WITH FROM RAZE 1 IS THE BEST. How to kill raze soldier: hit him with the holy grail and finish him off with the rocket launcher.
TIPS FOR WEAPONS: to get credits, play quick matches, juggernaught, easy :P
Ripper, keep the uzi, zapper, assault bouncer, holy grail, destroyer and DON'T WASTE CREDITS ON EXPLOSIVES, KEEP THE ROCKET LAUNCHER! those are the best weapons. To kill the raze soldier, shoot him with the rocket and then shoot him with the holy grail.
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