Live Action Experiences
Usually I make games that you play using computers or other electronic hardware, but over the years I've also created experiences in physical spaces. Here are the three I think are most noteworthy.Queen for a Day (2012)
a piece of participatory theater with a cast of about two dozen, custom-crafted for a single, unsuspecting person to experience on her fiftieth birthday

The FountainQuest (2008)
an elaborate, slightly puzzle-based, participatory theater scenic walk and marriage proposal
The subject was given, during an ordinary meeting with a business client who was in on the scheme, a FedEx package which had allegedly just arrived for her. Inside was a book about the fountains of San Francisco, a playing card, and some mysterious instructions to meet with a contact at a prominent fountain in a nearby plaza. The business meeting was adjourned and she was sent on her way.
This kicked off a journey which would take the subject to many of the fountains of downtown San Francisco, also including a lunch, a streetcar ride, and a chauffeured trip in her own vehicle. At each step she met people acting in character, be they friends, acquaintances, or complete strangers, who entertained her, told her cryptic things, and directed her to new places. There was a Clown to be found, and a mysterious Steward (that was me). She acquired four keys, and thirteen more playing cards.
Eventually, she received a specially constructed puzzle box which required all four of her keys. Inside was a hotel card key. The box also had a false bottom, which was revealed by the marriage proposer upon their meeting at the hotel, and which contained a guide for using the playing cards to reveal a secret message - that was the proposal.
This event was planned over the course of about half a year, staffed entirely by good-natured volunteers, and surreptitiously, extensively photographed with a powerful telephoto lens usually located a block away, allowing for the creation of a commemorative book after the fact.
She said yes, by the way.

The Solar System Perspective Project (2004-2007, 2009, 2012)
a three-mile long exhibit of humbling scale
The SSPP is a scale model of the solar system, with both the distances and the sizes of the planets at the same scale so that you can walk around in it and see for yourself exactly how empty space is. The planets are recognizable household objects - a cue ball, a marble, a peppercorn - which are each accompanied by a humorous informational sign, and these are spread out across the three miles of Stinson Beach in California. We've mounted it six times, typically over a long weekend, and it currently resides in my garage awaiting the next convenient opportunity. I'd go on about this, but it has its own dedicated web page already, HERE.
* Special acknowledgement to my old college pal and frequent collaborator Patrick Mundy. I did all three of these projects with him.