I use to make some pretty fun maps in Halo 3 back in the day. I didn't have online at the time, so it would only be my friends that got to play them, but it was really fun! I actually had one that was a similar idea to Shifty Station, it was a huge labyrinth with really high walls, and every couple weeks I'd rearrange the set up when it seemed like people started to catch on to the design.