There were also FM Towns, Mac, and PSP versions. They also left out a few different releases and the multitude of expansion packs.
The PSP version is a Genesis port on the EA Genesis compilation disc. 
And this competition is stupid.
Oh really? If you want to nit pick, then at least get it right. It was in EA Replay and was the SNES version with 'The Secret Missions' expansion (which I believe wasn't on the Sega CD version). Either way you slice it, it was available for the PSP and other systems not mentioned in the contest, so every game and every system obviously isn't quite accurate.
And all contests are stupid. Why would anyone want a chance to get something for free. 
1. I wouldn't have known, because that EA collection has a high shit-to-value ratio ensuring I'd never buy it, and from seeing all the Genny games on the disc I assumed it was all Genesis.
2. This contest IS stupid. Why do I want to win most of the systems I own again? Also, ISOs and roms can be downloaded, DOSboxes can be opened, emulators can be activated for the systems I don't have. This seems to me like "Jeez, how can we get rid of all the WC shit we have lying around?", but blog contests always suck and I'm wasting my life debating this with you so I'm not even going to give your a proper witty ending statement because you don't