To spice up Super Mario Advance 4, the 2003 GBA port of Super Mario Bros. 3, Nintendo released a series of e-Reader cards which which enabled players to load new stages and power-ups, provided they had a copy of the game, two GBA systems, a link cable, and the gigantic e-Reader+ add-on.

Because of that complicated and expensive setup -- and because different region-specific and region-locked cards were distributed randomly in game bundles and card packs -- it's unlikely that most gamers who picked up Super Mario Advance 4 ever saw all the e-Reader levels, much less played them. It's a shame considering they include elements from Super Mario World and Yoshi's Island, and they're the only Nintendo-designed 2D Mario levels that were released during the decade between Yoshi's Island and New Super Mario Bros.

NeoGaffer Mama Robotnik, however, reminded me that someone ripped and posted full maps of the 30 stages, so that if I want, I can just put my fingertip up to the monitor and pretend it's Luigi jumping through the level and collecting coins. I'm not saying that's something I wasted my entire afternoon doing, only stopping to write this post after I kept dying on one of the Airship stages, but if that turned out to be something I wanted to pursue, the option is there.