I'm sick of the comments that say that leveling is too hard. It's not hard at all up to level 120, and with 600% boosts it's easy to 300. Then just save up 100mil (for the Almost Missed achievement) and buy it.
This game is like a black hole, but better. :P
The farther you go into it, the more you are sucked in. Right now I'm at level 301 with 97mil. I feel like the 700% boost thing was made for me, because I hit 300 when it was released... :3
To get all the gadgets you need 27 tubes, 10 smokeless powders, 10 springs, 11 batteries, 26 plastics, 11 electronic parts, 33 steel chunks, and 11 kevlar.
Screw this game, if you are really lazy enough not to remove that ad, then you really really suck. 2/5 just for that, impossible to kill people from below with psy powers.
I only have two suggestions. 1: More vehicles. I'd love to drive a tank or hummer around this city. 2: I wish you could shoot from the car you get. I mean, can't he steer with one arm and shoot with the other?
I'd recommend investing in idle mode. It may not go as fast, but it stills goes a LOT faster. By the way, it cost me 1.4 million coins to get it from 40% to 80%...
 "Anti-Idle: The Game"){kind=icon}
 "Dungeon Cleaner"){kind=icon}
 "Friendly Fire: Blood and Gore"){kind=icon}
 "Body Ladder"){kind=icon}
 "zombie horde 3"){kind=icon}