In 2012, a playable teaser for the highly acclaimed Portal 2 mod Portal Stories: Mel was released.
I worked as a level and puzzle designer and was responsible for blocking out the entire teaser level. The level was then handed off to other team members, who addressed technical issues and made a complete art pass.
Tools: Hammer Editor
Subscribe on the Steam Workshop (requires Portal 2)
Note: I left the team a few weeks after the level was publicly released, as I no longer had enough free time to continue volunteering. While a rendition of “Past Power” still exists in the final mod, it has been heavily modified.