Crystal Orb Adventures is based on an old ZX Spectrum game.

The original game, The Orb, was published by CRL way back in 1982, available at World of Spectrum
Please note I was only 6 years old when this was released and thus have nothing to do with its creation.
I just really liked it, even though it was slow and written in BASIC.
I went on to make a sequel on the Spectrum (in BASIC), another one when I got an Amiga (in Blitz), and another one when I got a PC (in Dark Basic).
They were all simple top-down graphical adventures.
But now, with the power of Blitz3D, I can program what I always wanted to: a text adventure game!
Look, it was either this or 'Crystal Orb Tactics'.

Apparently, the game was previously published by ASP Software under the title The Valley (over which there was a copyright issue with CRL); the programmer was Dominic Ferard, so kudos to him.