Hmm, I was working on one with Games Factory, but it was rather difficult. In order to have the small mario big mario, i actually had you controlling all of the different marios at the same time (My Marios were small mario, Big Mario, Mega mario [like triple the size of super mario] Fire flower [shoots fire balls], Thunder Flower [shoots bolts in three directions] Ice Flower [never fully programmed]) and all of them would be set to invisible, and be switched off. Then when there was a collision event with an enemy, any mario above small mario would turn invisible and small mario would turn visible and be switched on, and similar events would happen for power ups, except of course the Mario turns into a higher form. I made a pretty convincing level, too. Lol the best Paint Shop Pro Mario substitue graphics you'll ever see. Sorry for rambling.
Kweeh! Forget Whark! Kweeh! Is better!