If you REALLY want to delve into Blackwell, the very first game that inspired the full series of commercial games was a freeware game called [b]Bestowers of Eternity[//b]. AFAIK only "Part One" was made, and then Dave shelved further development of that in favour of creating the first Blackwell game as a commercial venture.
BoE is still available as freeware and it's interesting to see what started it all off.
http://www.adventuregamestudio.co.uk/site/games/game/304/Thus began Wadjet Eye Games... and the rest is history!
(Just checked the link, the main download didn't work but the AGS Archives one did. Can't beleive I played that game over 12 years ago!!! :O)