this game could be really much beter the challenges simply sux... especially 4,7 the "shield" is always running away even when you klick like insane i made it after like 40 tries and it had nothing to do with skill, but only luck, robots should be controled with arrowkeys.... 3/5
finally i got the easiest way to win 40 days: get first or second round uzi+3 gunmen. than rush the 5k gun,after get 2-3 repairman and 1 upgrade an rush 1 quake box at lvl 3 keep repairing your main, after get level 4 main and rush 2 missile towers and keep upgrading them. if you have gold left get some more gunmen/repairman. only thing you have to do is to destroy those suicide vens. for the last mechs replace the quaker with a laser.