If u die in a wave, u can restart at last wave, but u keep all the money that u got in that wave, so u can farm waves for 90%, then die, and get huge tanks at low lvls.. kinda buggy:P
WTF! i was on my 8th day all i bought was the second sleigh (skipped the first one) and then some arcade thing showed up on my screen and now i made 2k money in 1 day coz i got 5 speed challenges and 1 distance (i used to make 50 dollar a day, this is 1 sick random event)