You could make it so all humans have the same numeric stats (intelligence, strength, agility/speed) when they enter the place, and as they explore and find artifacts, it may decrease or increase. The total value of your stats are known to you only though.
Say, then, everyone starts with 3, and player A gets an artifact that boosts his intelligence by 1. Then player A has 4 intelligence instead of 3, and you could make it so player A gets a slightly more detailed description of the room, or has other rooms in his map visible (since he "memorized" the path or something similar.) Someone with a higher agility could eventually move more rooms in a round (or run faster should anything decide to fall on our heroes), and someone with higher strenght could "beat" someone with lower strenght (although gathering two people whose sum is larger than the boosted player would still cause him to lose.)
Consequences of losing could be thought later, too.