I wasn't around earlier to tell you, due to SA City (NOT Station Square!!!), but my 3rd WAD was a 2D Toxic Caves, which was, incidentally, a single player level. This is before Green Hill DM Zone and Jason's Base, so I didn't know how to make FOFs, but it actually had multiple routs: Flying through the air via springs and Running along the floor. Then in the second level, you moved via long strings of rings and Adventure mode. It's outdated now due to only Sonic being able to lightdash and stuff, but I guarentee it can bring a good 30 seconds of fun. :P