This is highly addicting, the controls where smooth and the upgrade system wasn't that bad, but the game play was some what too easy like, you should have given it some thought to put a difficulty scale in the game just to make it a wee bit more challenging. Also i agree with Ralfo perhaps you could up the AI make it have a better strategy.
yesterday i was at level 5 with my exp boost and it wass giving me 100 per boost and it was going up at a million mph now its going up super slow but giving me 1000 exp per bonus same with the money was giving me 60 now its 600 and its level 3 is that messed up?