The gameplay is good, the runes are distributed cleverly in the dungeon. One thing that didn't work : botas didn't getful when put in a fountain.
No really original weapons, but somehow, the dungeon makes sense and plays well.
Originality: 8
Ok it's only a 8 because there's no custom weapons or spells. BUT :
New monsters with original attacks, original puzzles, good storyline, hints from LEXUS... all that is just great !
Difficulty: 10
Well the dungeon is difficult, but never unfair. If you're well prepared, you won't die stupidly (except down some pits

Puzzles: 9
Puzzles are nice, no real red herring but some do require a bit of thinking (or hints from Linflas

Size: 10
Only six levels, but what levels ! The dungeon feels big, because every tiny space is used. Somehow everything has the size it should have to look good in DM, no less, no more.
Replayability: 7
You can chose other heroes and complete Ruby or Sapphire in the order you want, so it's more replayable than any other dungeon except Conflux. But honestly, I don't really know how to mark, because aside from conflux, where replayability is infinite, most dungeons are a one-time game. Even CSB lost a part of its mystery the second time...
Craft: 10
In the beginning orienting is not too hard, but as you progress, new ways open and the dungeon become a big Swiss cheese, except you don't know in which hole you are. I felt even more lost than in Surgical Strike, because of the intricated design of the dungeon. The game mechanics also plays without problem, not once was I stucked by doing something weird in a puzzle room. Really well crafted !
Game Ending: 6 or 8
...depending on the stuff you have. I suppose that if you don't grab the correct item, beating the boss is almost impossible, unless having 4 good level master wizards and priests... But other than that I liked the ending, the story is good. And I stole stuff to the damn master so I feel happy

Atmosphere: 8
The story line and Lexus really puts the player into the game. The new monsters, and the DM2 graphics are integrated to give a really anguishing atmosphere, everything just FITS.
Overall: 9
This is one of the best dungeons I've played especially because of its graphics and originality. You can play it casually an advance everytime you load a game. No "I've been roaming for 5 days doing nothing" situation !
Best part:
Well, I don't want to spoil. I liked : Lexus, the Guardians, Dragon Lair.
Worst part: (out of a very good dungeon )
Some really hidden buttons.
The end has less clues and interventions from Lexus, compensated by the wallsets, monsters and overall frightening atmosphere.