Not bad, but I reached a point that was impossible to pass. The moving corridor didn't move fast enough to get to the next section. From when it appeared at the top of the screen to when I died at the bottom there was never an opportunity to progress. This was at ~600 points.
If you're struggling with the Winter Games levels for the 10th anniversary badge, play the normal game a bit further until you unlock the lizard. He jumps really high and moves slower which gives you more time to adjust your jumps in the winter stages.
After finally coming back and completing this badge, the only advice I can give is to take your time. There is no time limit and the only thing that causes more balls to come is by making a shot that does not clear at least a group of 3. Wait a few seconds after each shot, as sometimes the game can glitch out and think you missed more shots than you actually did if you shoot too fast. Good luck.
I respect the fact that the developers want to make money, but I don't think this is the best way to do it. Look at something like the Bloons TD games... They give essentially full access to the game, but by supporting the developers, it becomes so much more fun. With a demo, it's kind of a slap in the face once you reach the end.
I have to use the space bar to start a practice game, but then I have to use the mouse to move on to the next practice game? Why can't I just use the space bar to continue?
A good game with a few minor flaws. 4/5
If you're having trouble getting money, try using the vortex+bfg combo on levels where you need 200+ kills, it's much easier to get most of the money in a level by using that combo.
It would fantastic if I could just use the mouse controls for single player instead of having them restricted to player 2 :(
Other than that, great game! 4.9/5
I updated the game. Now, when you finish it you have the option to press 'N' to skip any level.