http://www.hardcoregaming101.net/technocop/technocop.htm

This driving/shooting game by Gremlin Graphics had the questionable honor of introducing explicit gore to home consoles, years before it became a big issue with Mortal Kombat.

http://www.hardcoregaming101.net/tattooassassins/tattooassassins.htm

Data East's pinball division tried to make their own Mortal Kombat II ripoff with Tattoo Assassins. We say "tried" because the game technically never came out, but it's still a testament to the absurd excess of the 90s fighting game market.

http://www.hardcoregaming101.net/baraduke/baraduke.htm

Gamers were shocked when Samus Aran revealed herself to be a woman at the end of Metroid, but technically Namco's arcade space shooter Baraduke beat Nintendo to the punch.

http://www.hardcoregaming101.net/adom/adom.htm

Ancient Domains of Mystery seems like a standard cRPG, and has many things in common with the genre: overworld map with towns and dungeons, quests, karma system. But the game is also a traditional roguelike with the level of complexity and difficulty similar to that of NetHack.

http://www.hardcoregaming101.net/500wordindies/500wordindies-cotsg.htm

Developed by Italy's indie game scene, Cast of the Seven Godsends emulates arcade classics like Rygar and Magician Lord, though with visuals that resemble a high-res Amiga game.