(Again showing my age)
I had one; it came out when I was a teenager--and I remember it had a lot of hype when it first came out. This was a time in which add-ons were becoming popular for console systems. The best-known one outside of the 32X was the game Sonic and Knuckles, which was a stand-alone game, but you could attach other games to the top of it (primarily meant for Sonic 3, but you could also put in Sonic 2 and play it as Knuckles. Or you could put in any Genesis game and play different bonus stages.)
At any rate, the 32X didn't do well at all. The only game that I remember being good for it was Mortal Kombat 2, though there were a couple other good games.
This was also at the time when the folks at Sega, Sony, and Nintendo were just starting to looking into disc-based games. There were all sorts of debates on which was better. The Sega CD system was the first to reach a wide audience in the US. The PS1, of course, was the first to make a huge mark, and the rest is history.
