So you want the all mighty bertha but you maty need help so here is a guide to help you
1.crowd pleaser,this achievement kind of just happens but if you need help you can kill multipul enemys at once or use a trap like a shock trap,rocket trap,laser,ect
2.shocker,just press all the buttons that set if of but 1 and wait for a guy to walk over it and press it and ....zap!
3.explsivo,just like the 2nd achievement except with a bang!
4.fricken' lasers,again like achievement 2 and 3 except with a zzzzzaaaaappppp!
5.centurian,its not that hard just do the level ware you need to kill 100 guys
6.saboteur,Buy a proximity mine lancher for 15000 dollar fire it alot and evenshuly someone will die
7.fireman,buy a burninator for 5000 dollars and burn em up!
8.shutdown,buy a emp launcher for 25000 dollars and shoot someone or it is posibal for a guy to launch one and it hits someone else and you will get the achievement
9.failure,just sit around and get blown up easy
10.entertaner,i did this achievement on level 9 just drive over the buttons over and over again and you will get it easy
11.hoarder,just do a level with alot of big guys and thay give alot of money so you should get it fast
12.big money,well by the time you beat the game you should have it and you can spend as much is you want of it it goes by how much you have colected not saved
13.gun nut,Buy 5 m1 repeters (or any other wepon m1 reapeters are just the cheapest) and then sell them or whatever you want
14.prepared,just buy 5 explosive shilds (or any other gear thats just cheaper) and sell em or whatever
15.runnin' hot,i used a burninator (well 4 burninators) and you don't haved to overheat the gun, stop and then overheat again just hold down the mouse and the spacebar at the same time and you got it
16.domemaster,just do the same thing i did in achievement 10 on level 9
17.i come in peace,on level 2 just run over peaple and use traps and don't fire a shot and you got it
18.juggernaut,just get alot of money and buy the upgrades a good way is after you beat the game just beat the boss over and over again and bam you got alot of money
19.freedom,beat the game a good way to kill the boss is that he does not move vary much and may stay on a trap like the emp trap and the rocket trap
20.slaughter master,use a burninater or and explosive wepon get a group of guys (its bedder if you kill walking guys like on level 9)shoot and hope for the best
