The Pencil was probably intended to compete with this:
http://en.wikipedia.org/wiki/Mattel_Aquarius

Colecovision vs. Intellivision = Aquarius vs. Hanimex Pencil

Never heard of the Pencil either but I remember magazine ads for the Aquarius at the time.

Both of them lost, by 1983/84 (in Denmark anyway) it was all ZX Spectrum/C64/Amstrad CPC 464.