Very unique and beautiful concept map, and superbly done. I love the style and textures, and of course the excellent construction (clean brushwork and lots of small details).
I'm not much of a fan of those button-based logic puzzles (yeah, I'm too dumb for them), but I managed to solve them fairly well - mostly by random pressing. It's great how the machines work, the effects and all. Finding the last skulls had me stumped for quite a while, because I wrongly assumed the skulls in the main hall are placed in a progressive order and thus kept looking for in the wrong places. Increasing the brightness helped a lot, although the general light level is fine.
Maybe there could have been even more puzzle variation - if that's possible with Q3A and it's supposedly limited set of functions.
WTF at the ending, though. I spend ages in that cave trying to find a way out, when there apparently isn't (judging from your walkthrough video)?! The voice didn't help. There should have been some visual clue to make this absolutely clear to the player. Or is this the ultimate puzzle? A meta puzzle, so to speak.
Not that I'd have the right to complain - after all, I made players wander around a (Q1) puzzle nightmare myself...
Here is a
demo. Be warned, though: it contains long periods of not doing the right things and not searching in the right places. Plus the entire end debacle. If there's some sort of 'fast-foward' option in Q3A, make sure to use it.
I will have to noclip around the map and take a look at the source some time, too.