Some time around 2001 to 2003, Happy Toe Productions worked on "Project Brain Tracer", a biometric control device for SCEA. The studio also developed this prototype game, Aibo Verse, which was controlled through electromyography (EMG), electrocardiogram (EKG), galvanic skin response (GSR) and electro encephalography (EEG) signals. Presumably, the concept had some relation to Sony's robotic dog series AIBO.

In this prototype for the PlayStation 2, players controlled a dog around a small planet, interacting with characters and the environment. Apparently, another possibly related prototype called Sand Man was developed, according to the resume of Happy Toe's former game designer and artist Doug Cope.

You can see video of Aibo Verse in action below, as well as more concept art on Unseen 64.

[Update: Shortly after this post was published, the video was marked "Private", as was Unseen 64's post.]