Neat piece of work
This is a nice idea for a game. It kind of reminds me of something, but I can't put my finger on it. The style is good and the gameplay was very fluid.
The difficulty was a little shallow after a while. Alot of the levels were merely repeats with different shapes. You slowly introduced new stuff like traps and extra lives and stuff and that's cool, but I think you should introduce some of these things sooner. The early levels are way too tedious.
And the AI of the spikes is just too predictable. Like a comment mentioned earlier you can easily manipulate the ball to go where you want and get it stuck. Or you can have it tail you so closely that it will follow your every move and won't do anything unpredictable to catch you off guard. I actually monstered through alot of levels with the spikes right on my tail, but because of that I was able to move freely around the maze. Just had to make sure that I was on the controls all the time and I didn't hit a wall and go backwards.
You need to beef up the way the spikes move a little. The way they move now is just too predictable and easily manipulated. Might I suggest giving it a more random movement, or even putting two or more of them just to beef it up a little.
Simple gameplay, but not enough variations in each level and not too much of a difficulty curve. Get some more things going and this will be great.