Have some problems...
The reason I don't give this a high rating is because of the factor that there is no quality control button. This means that the game lags for me when I get a lot of balloons on the screen. I also find the dart upgrades are extremely weak for the cost that they require (6000 for one of them!? That's TOO much). I'd also suggest a less steep difficulty curve because the only way I managed to survive past stage 4 was to get golds in the earlier levels.
Overall, good game but it needs a lot of tweaking in order to be a truely decent game.