Zero for you!
This game, in 99% the times you play, is impossible. I got ALL the upgrades and still couldn't win. I want to punch the guy that made this game 'cause it's ridiculous...I was with +20k gold and it didn't made me nothing. The units(allied and enemies) appear so randomly that if you don't be careful you can lose at really a really low level, and at the high levels, they will almost not appear, if there is no unit for you to shoot at. At lvl 40 there was not a milisecond I could stop shooting, enemy units didn't stop spawning at all, and if a allied unid showed up, I could get him to the end, but couldn't pass the enemies because they were infinite and spawned at a rate you can't possibly kill even with all the upgrades...Ridiculous