Pretty Cool
Rank - 1 Pixel Perfect, Max Pixels - 63,445. The highest stage I got to was 9.
At stage 9, this game became basically unplayable. I couldn't even see most of the pixels, let alone distinguish between the specials and normals. 8 was pretty bad at the start, but got better as the top 'base' built up a little bit... On 9, I was dead in minutes, if not seconds.
Before about stage 5, the best strategy I came up with was to intentionally hold off beating the stage and growing your 'tree' out along the sides... Up until stage 5, when I began the next stage my tree was wide enough that I could have sat right in the middle of the screen and not missed any pixels.
After the pixel rain on 4, though, continuing the strategy was nigh impossible. Starting on stage 5, the only real strategy was to move the mouse really really fast, and to sit under the concentrated rain areas when they happened... Mostly move really fast though.
As others have said, good music choice. It fit the game rather well.
The backround color switching on stage 9 made it even harder to see the pixels on most of the colors... Please take a look at it and perhaps change the colors?
From 5, +1 for the music, +1 for originality, +1 for simplicity and clean gameplay (before stage 7-ish). Another 1 because I liked it so much ^^ Good job all around!