Getting back to porting backgrounds, starting with Chemical Plant Zone. I had considered adding water, but decided against it for now, because unlike Labyrinth Zone, CPZ's water doesn't affect scrolling. I've also updated several levels to make them run faster, and added some new API stuff to the screensaver (which CPZ uses), so you may want to redownload everything. @Blivsey: does it still happen after the update? If so, where exactly? Edit: fixed bug with tall screens in CPZ.