Hm... 24 days, 8 days / world. Wished, the flash-version would have had more levels. But I guess, the publisher wanted this restriction. I remember the 1st part, where I had a bit more fun than now. It's just "Buy pumper, buy best gear, buy best engine". Then: "Buy wheels, fuel and then boost". 1st level: You don't need to buy whether boost or gun. Maxed, one is enough. And make sure, to drive in a 30° angle, so you won't have a real break.