I can't believe I haven't played that mission before. I finished it today and Curse of the Ancients is indeed a forgotten gem. I agree with you about the underused spaces and for me this is the only flaw of this mission. Otherwise it's a spectacular achievement and we need to remember it was made in 2000. I really enjoyed solving the puzzles in the tombs, they were pretty much straightforward and I never felt stuck for longer than a few minutes. Exploring the haunted city was a sheer pleasure...