Just rotate the tiles until there are no breaks in the pipe, making an infinity loop. (There can be multiple loops in one level) Click to rotate the tiles, when you finish the level the color theme will change, just click to advance to the next level. Currently there are 25 puzzles. More may be added in the future. You can press L and type a number to skip to a level. (Possibly a level editor in the future?)
This is based off the mobile game Infinity Loop. I created all the tiles/art in Photoshop.