Don't take turrets. Take shields. Play with big ones not letting them hit you or fly away (hit the side where it is moving to stop him). It took me 3 big circles (each for 3 minutes almost one after another) to win the hard badge. 633 seconds. Easy :)
Badge won in 2 tries.
Tips:
Don't buy shotgun and uzi. You can go with pistol until day 6 or 7. Buy rifle. Then minigun.
Every day gives you 5000 points, and difficulty bonus is also 5000 so at lvl 15 there should be enough points to get the badge. (i've catched a bug with "freezed" robot at day 22 so i killed myself to be able to finish that day).
Shoot fast moving targets first. Gather targets near exploding robots than kill them.
If this comment helped you - repost it for others, please :)
Hate the last level ACE switcher. More than 100 attempts to switch it and then to escape... almost impossible and a pure luck. 15 level really aced (almost with closed eyes) except for that switcher part.
Tetris should be fast. This one is not. Remove keyboard lag, add instant line dissapearing - than it will be tetris. But still nothing new. No graphix. No additional elements. Really nothing.
fishtastic, i can' beleve my eyes. Morethan a half of your comments are here. And all of them about rating. This game is not "simple" and not "simple coded" :) And everybody see it. Don't try to lower the rating. By the way, is it you who creates a 10 accounts per hour and votes 1 for this game?