C'mon.
There's the necessity of a developer to make some cash for their hard work, but there's a line you can't cross. This game crossed it.
You shouldn't HAVE to pay money to win the first few rounds. Heck, you shouldn't even have to pay money to beat it. The computer doesn't have to pay money or grind the first level to get those arrows that they toss around like they are nothing, why should I?
I really like this game, but I have a big issue with needing to pay you to beat the computer. If you need money, just charge $5 and make it a downloadable game. Coulda been a really fun time waster.