For fun, I’ve written some role-playing game adventures and designed a few games.
I wrote “Prison of the Mad Gods” for Dungeon Crawl Classics RPG. You can get it in PDF from DriveThru RPG, and in print from me (link opens in a new tab) or from Goodman Games.
I’ve also made an expansion for Pelgrane Press’s space opera game Ashen Stars. The expansion enables you to play criminals uncovering secrets in a gritty space opera setting. It’s available from DriveThru RPG as a PDF, and I’m working on a print-on-demand version that will have more illustrations.
I also wrote “Apex of Life” for Trail of Cthulhu, but it’s unpublished.
Back before Adobe Flash died, I wrote Daedalus, a fast-paced 2D race/maze-building game.
Finally, here are a couple chess variants: Zombie Chess and Alien Chess.