Chalice is a 44 page arthurian rpg run on the Trophy engine. It's GM'd, multiplayer, and no prior knowledge of Trophy is needed to play. You do need a deck of tarot cards, though.
In Chalice, you play as knights questing for the grail. The grail is unattainable, and over time your failures and flaws will add up until you lose sight of it and choose a different path.
The Trophy engine is designed for slow-burn horror, and Chalice leans slightly in that direction---but instead of horror, the threat to the PCs is dishonor and worldliness.
Setting-wise, Chalice leans a fair bit into the arthurian supernatural. You could almost certainly use this game to run Dark Souls, and there's a noticeably grand and tragic air to the snippets of gameplay that the book describes.
The game also comes with a scenario, The Cathedral of Green, which is evocative and solid.
I think my only critique of Chalice is that one of the central conceits, that the knights give in to sin and do not succeed, is going to feel forced if the players play to succeed rather than to destroy their characters. It's really worth getting everyone on the same page before playing that the goal is to lose stylishly, not to win.
Overall, though, I would strongly recommend this to anyone who likes arthurian roleplaying, or who wants to see some more of the versatility of the Trophy engine. It's well-written, atmospheric, and a cool alternative to overt horror.