Thought I might as well report an almost-game-stopping bug I experienced. It's a total edge case, so this might be just for amusement-value:
I was carrying the smiling idol down to the far lower cave (bottom of the map, below the previously standing yellow barrier). On the way there I carelessly let myself become covered in many many cream-puffs. Entering the cave triggered their explosion sequences and I reached the chest, opened it and clicked on its contents at just the moment I succumbed to darkness. When time and space agreed to take me back I respawned outside, and naturally I was still carrying the idol and didn't have the chest contents. But, oddly, the screen was still a faint red and I couldn't move (either with keyboard or mouse) though the cursor was still visible (and I believe would still turn into the movement arrow upon left-clicking). In fact, the entire GUI was missing (map on the lower right and inventory/self button on the lower left). Escape still quit to the main menu, but choosing to resume the game from there would start me off in the same broken position. Luckily, quitting the program completely and relaunching fixed everything (though there was some weird behavior in which the chest contents jumped immediately into my inventory upon getting within grabbing distance).
This is such a great game, by the way. (You mention Zelda and Ultima, but it seems to me that the Twinsen/Little Big Adventure games might be the most direct influence, no?)