Well
No matter how much I play this game over and over in every version, it just is never fun. I think you've taken this idea way too far, and it's not as great of an idea as I think you thought it would be. I play a certain area, and no matter what I do it seems like it can never, ever hit it right. There are certain maps that I think you thought could be done with a few clever shots, but no matter how many times I try, it never works out right. I'm on 17 right now, and every single damn time I get down to one dart left and the only balloons left are on the top row, it can never, ever be thrown across correctly.
This exact game has been running for so long that I expected some actual variety and choice by now. You should let the player choose different things for maps rather than only letting the player use a special dart only by hitting a power-up balloon during a puzzle. Have more complicated objects that do more than just block your path, and allow multiple possibilities for solving the puzzle. Maybe the player could choose a lobbing dart like what is now, a bullet that goes faster and farther but can reflect off of many surfaces instead of just the spring, an exploding arrow that explodes on contact with something in a 9x9 area, or a laser that can go forward right through most blocks or walls. And most of all, have different projectiles not just in power-up balloons, but perhaps a choice while the player plays or something the player can "buy" from points he gets during puzzles. This was a clever idea back when it was first released, but it's been 7 games and two years of the same thing. I feel like I have no control in the game, and I don't like that.
On level 10, it took about 25 minutes, yes 25 freaking minutes, just to get ONE dart to reflect and NOT only hit the very top-left balloon in the 5x3 area. Again and again and again and again with hundreds of darts and it would NEVER bounce off the spring at the right angle. I dunno about anyone else, but that's infuriating to me. Again, that wasn't "challenging". It was just annoying.
I know users are considered hateful here at NG when they vote lower than 10, but it's useless to only vote one number without ever giving your insights or opinions on flash. I'm not trying to be mean, I just couldn't get into this game yet again. Here's hoping this goes through a huge change before it's uploaded to the Portal again.