Ever since I was a kid, I always liked to make my own variants of existing games. I remember we made a huge RISK map during a hot summer, expanding the number territories to several hundred. Unplayable, of course, but as kid, you don't realize that yet. I also made my own variant of Monopoly, adding shares for companies and a stock market. And racing games using Matchbox cars or Cyclists, emulating the Tour de France (some more examples here). I guess I never stopped doing that ;-)
From the digital archives, I recovered some files for a game called Superheroes: The Wars of Destruction! The was a game I made together with my friend Eric B. If I remember correctly, we made this during the 93-94 Christmas break. We had attended EuroGencon that fall in Camber Sands, at which Magic The Gathering was launched in Europe. We were addicts immediately. So, we came up with the idea of making our own variant, using Superheroes as the theme. Eric had a huge comic collection, so we spend quite a few days scanning images, and designing cards. No mean fate with the computer power of over 20 years ago.
We printed and mounted close to 300 cards (we printed our cards using various coloured papers, and glued them to ordinary playing cards), and distributed them among a handful of friends. We even had "starter decks" and "booster packs". Of course, the idea never was to make a commercial game, we did it just for fun. We even included ourselves as "superheroes".
I lost the original files long ago, but Eric had always kept the printouts, and they resurfaced recently. Some examples below ...