I have periodically helped out with other people's games. Below is a list to anything I am credited in, and where you can buy it. Newest at the top.
Gem Wizards Tactics is a charmingly delightful hex-grid tactical strategy game from my friend Keith Burgun, and you can purchase it on Steam (external link). I contribute periodic bug fixes, code polish, Steam integration, and macOS testing on a presently ongoing basis.
Open Sorcery: Sea++ is the follow-up to Open Sorcery, and a multi-layered text adventure through programming in the spiritual world; you can purchase it on Steam (external link). I contributed significant bug testing, with an emphasis on the macOS build.
Auro is a tactical monster-bumping adventure; you can purchase it on Steam (external link). I contributed bug testing and some code polish, such as Steam integration.