I understand you wanna get paid for your efforts and I'm ok with that, but some strange microtransaction system shoehorned in at the last second isn't the way to go. No one and I mean NO ONE is going to pay you to play the game for them. Flash games are ultimately short time wasters and pouring money into something like that seems like a short sighted impulse buy, especially once you're done with the game (which is apt to happen the same dang day).
You're only getting these points because you resisted the urge to force coin spending to actually beat the game, but you came dang close. It's a dangerous precedent you're setting buddy.