Usually.
1) Time > How long does it take.
2) Loots > In this case its more "Easter Eggs/Hidden Objects", as in objects and clues not obvious to find. (No random treasures here.)
3) Methods > What ways and how you solve puzzles/situations.
4) Goals > How many goals have been accomplished? If there's more than one.
Usually its separate groups going through the same dungeon, sometimes with pre-gen PCs for "fairness", and then you tally up the results and compare.
Easiest way would be room-by-room straight line dungeons, with one theme each room from either "Skill/Trap", "Puzzle" or "Combat"
Putting multiple groups in same dungeon, you'd get at least a few who wanna turn it into a PvP arena.
PvP arena, or pure "Horde Survival", could be a thing too.
Anyhow you wanna make it as close to zero-learning/prepping on the player side as possible.