when facing the return wave u use weak guys (zombies/goblins) to retreat ur guys (only retreat ranged) (Mainly the cannons) then crush them with your full forces. this is how u win the last levels. Also be aware of Bosses they arent over powered but with them and some other units they can kill u
great game but over used idea i give 4/5. i know people dislike these games cause they are insanly hard (Which they are) a couple tricks or hints. always be watching your ship, never ever watch the enemy ships especially in the boss battles. ull die if ur watching the bosses health
really i would have given 3/5 or so if u put actually on line and not online but this is just stupid the halo communty (ANYONE WHO PLAYS HALO) hates this stuff 1/5
wow nice game is this ur first??? perhaps next time a survival mode more variation in graphics and weaken the gun towers (seemed a little to strong for thee amount of money) but if ur first game then 3/5 if not then 3/5!!! :)