2nd laser and same upgrades. Buy repairmens to 20 and max wall upg. At last (day 28-29) change shotgun to "Old glory" and uprade it to max. After that buy 10 more repairmens. Stage 38-40 may be little difficult, because many lags. Good luck.
For HARD badge: Day 1- buy 3 gunners, day 2 - 1 more gunner, day 3 - shotgun, don't waste money for upgrade, day 4-8 - 21 gunners, 1 repairmen. day 9-12 focus jeeps and groups with shotgun, buy gunners. day 13 - you must have about 43 gunners, 1 wall upgrade, 1 repairmen, shotgun w/o upgrades, now relax few days, gunners will do all job. Stop buying gunners at 50. Now you need missile tower. 1st - max fire rate, 2nd- number of missilese, 3rd- damage. At day 17 need catch big truck, now you need to help with defence by destroy the trucks (shoot only in trucks, your defence kill all others). You may buy 2-3 repair mans and 1 more wall upgrade if hard to catch tracks. After max missile turret, buy 1st laser, max fire rate then damage. Now you need 3rd-lvl walls and 10 repair mans. After you may skip trucks :) (but kill is better).
Easy way for 180 sec achiements! Start the game, switch to another window (ctrl + tab) Wait 4 minutes and go back to the game window. I wish you all good and light receiving achieve
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