great game and here are some tips:
1 do NOT get the fourth gun it has only 6 bullets at the beginning a complete waste of 6000$
2 get the SMG after wave 2 and the sniper rifle after wave 4
3 head-shots are easy with the SMG so use it to kill packs of soldiers
loved the game use the tips to your advantage :DDDDDDDDDDD.....etc
assault rifle ftw :D nice game too :D
Fun a few flaws but overall a fun game.
You can beat the game with only one weapon, but its fun to try the few other weapons out.
Upgrade the sniper all the way and pick em apart.
its pretty good except once you get good enough with one gun, all the other guns are useless.
i liked the sniper
word of advice, always take out the snipers first