Hide & Seek is London's first pervasive games festival, founded in 2007. Last night it hit the ICA with The Sandpit, a series of on and offline games exploring 'how growing up pressing buttons and playing video and online games has changed what we want from the culture we consume' - so Mike R, Si D and I went along to play.

The game we were really there for was Free London's Monsters, a project created by Andrew and the team from Blink Media using Thumbprint, their platform which allows people to read and write about their world by text message. To help FLM, you text the location, name and description of your monster to the platform, which allows you to 'own' that space in the city, where others can text in their thoughts, dreams, ideas, or indeed monsters... (mine is here).

Thumbprint has great potential: games are a brilliant leveller, and the combination of geo-location, playful offline meet-ups, social media integration and mobile technology has all the elements of the kind of immersive, sensory creativity we love. Flickr images from Andrew coming shortly.