Note that "Keen Dreams" is the game sometimes called "Commander Keen 3.5" or "The Lost Episode"; unlike episodes 1-3 and 4-6 which were made by ID for sale by Apogee, Keen Dreams was (I think) the last game ID made to fulfill their contractual obligations with SoftDisk. It's interesting in a number of ways - the engine and art is very clearly halfway between the first and second Keen trilogies, it's the only game where Keen doesn't have his iconic pogo-stick or his Neuralizer Ray gun.
"On October 24, 2005, 3D Realms (formerly Apogee) released a maintenance patch to fix a bug in the game which set the player's computer's clock backwards 100 years after playing on Windows XP." lol.
Secret Agent, anyone? I still love that game. In fact, all the old Apogee games had a sense of mystery and discovery that's sorely missing in modern titles. (Or is it nostalgia?) I remember playing through so many shareware titles and salivating at the new goodies that the nag screen promised from the remaining two episodes!
By the way, Apogee has released a lot of their old titles for free. You can find them at 3drealms.com, in the Downloads section.
