I, Monster was planned as a 3D movie using the Pulfrich Effect. Yeah, I'm not familiar with it either, but you can find out more about this interesting camera movement technique on Wikipedia. Brian McFadden in his Amicus Horrors, Tales from the Filmmaker's Crypt, notes that Christopher Lee wasn't keen on I, Monster, his last Amicus film, because of the constant camera movement the Pulfrich Effect required, which made editing the movie difficult. I can imagine the challenges with the setups for the camera were pretty vexing too and time-consuming.
