As a kid, I was a Nintendo fanboy but I secretly wanted to play Sonic the Hedgehog (don't get me wrong, Mario and Donkey Kong Country were great games). By the time I finally owned a Sega Genesis, Sonic 3 and Sonic & Knuckles came out. Now the latter game seemed impressive at the time. Sonic & Knuckles was a stand-alone game but if you opened the top of the cartridge, you could insert Sonic 3 and you unlocked new levels and secrets! Better yet, insert any other Sega cartridge and you ended up playing the bonus stage with different layouts depending on the cartridge you used. (Of course in retrospect, that kind of game developed not because they were brilliant but because the developers didn't have enough time to finish the whole game!) As a kid I thought it was so cool!
So that belongs to my list of all time blunders that did a reversal and cashed in on its flaw. An example of blunders that didn't make a reversal was this fighting game (I forgot the name) for the same console that was cashing in on the Street Fighter II craze and they thought hey, let's make our game unique by letting players control their characters via motion sensors. Think of it as a glorified dance pad before Dance Dance Revolution ever came out. Since we're still playing fighting games with joysticks and controllers, you know where that idea went.