I used to play this flash puzzle game all the time. I thought it was called "Bump" until I tried to search for it recently and couldn't find anything about it. It has you as a character who just moves by itself and you try to guide him to the end by spinning pipes that he walks through. I seem to remember the character being kind of robot looking but i'm not too sure. Anyway there were enemies that would also navigate the pipes and you had to make sure to not run into them. The goal was to guide your guy through to the end through various enemies and timing puzzles. It was a really neat game and I just can't seem to find it. If you've heard of it let me know!