A good implementation of a challenging concept -- with great gameplay to boot!
3-Demon is the kind of game where someone describes it to you as "3-D Pac-Man!" and you don't believe them. I mean, come on: 3-D Pac-Man on a 1983 PC? Give me a break.
So you copy it from someone else, boot it up, and there it was! Simple graphics, yes, but they were implemented well and presented the feeling that you were there, in the maze, with monsters, power pills, and a helpful local-area top-down radar to give you a fighting chance.
A frequently-overlooked key gameplay concept was the ability to optionally drop down to the next level once a certain number of dots were eaten by hitting the down-arrow key. At first glance, this seemed silly--you wouldn't get the end-level bonus if you did that, so why would you do it? Because if you were in a tight situation and had no way out, you could drop down and live to fight another day. Of course, the ghosts on the next level were even faster and tougher, so this was not a decision to be made lightly. You don't know about the hesitation between fear and courage you can feel until you turn a corner while pursued by a ghost, only to see another ghost heading toward you from the far end of a corridor. Many a time have I had two percentage points less than the level's threshold, hesitated, and then gunned it toward the ghost at the far end, eating dots along the way, hoping that I would cross the percentage threshold and smack the down arrow key before the ghost smacked me!
I could find almost nothing wrong at all with 3-Demon; it's a masterpiece for its day. About the only gripes I have are due to user error (the game trashes high scores if the disk runs out of space to hold them -- doh!) and modern technology (modern machines must be slowed down drastically to get the game to run properly). But none of these faults are the fault of the programmer, who did a fantastic job.
The Bottom Line
An early masterpiece that deserves to be recognized. An early 3-D gimmick and
decent gameplay? Unheard of in 1983!