Vaarn is a deceptively simple system that is incredibly fun to play. The setting is captivating - blue sands, a planet at the end of time, and countless generations of ruins to plunder. 

I used this system for a science-fantasy one-shot recently. It was easy to adapt my system-neutral dungeon to fit Vaarn. Because Vaults of Vaarn is OSR, I used statblocks from my favorite bestiary, The Monster Overhaul, to populate my dungeon. The monsters convert seamlessly to VoV's system.

Everyone at my table for the one-shot had played TTRPGs before, but none of us had played Vaults of Vaarn. We quickly picked up the mechanics within the first hour of play. We all had a great time. I'm looking forward to the next time I get to play, whether as GM or player.