The speed of the drag doesn't seem to affect anything, it just makes the dots more spread out. Why not draw lines joining the dots together? That's how graphics applications like Paint do their drawing.

The fades are performed by pre-calculating a look-up table of images. Each one is a copy of the original image (a ghost or diamond) but with an added alpha value for each of it's pixels (from 0 to 255). I only make around 10 to 20 faded copies of an image based on how fast I want the fade to be (a fast fade uses less images then a slow fade). This way I make as few images as possible and so use less memory. Then the Ghost or Diamond just selects which image to use depending on how it's currently faded (or if it's fading at all).

Thanks for the comments. I plan to add sound for the final version, some more enemies and a boss. I'm pretty sure I now know why it doesn't work unless your logged in and am working on a temporary fix.