24hoSMW V - return of the unnamed purple fortress

My entry for the fifth 24 Hour Super Mario World contest at Super Mario World Central. The aim of this contest was to create an automatic level - that is, one that can be finished without any player input whatsoever - within a time limit of 24 hours. This was my very first attempt ever at making an automatic level, and I think it turned out pretty nice, if maybe a bit short. I'd have liked to have a longer rainbow shell bouncing section, but I just couldn't manage to get it to work.