The Curse Of Dread Pirate Zar is a system-agnostic 31 page fantasy adventure. It has a super well-designed, phone-friendly layout, and it's got solid full-color illustrations throughout---including important maps.
In terms of sheer polish, Curse is quite strong, and its overall GM-friendliness is worth noting as well. Everything is linked, easy to find, and either covered with a minimum of words or given an overview that you can skim. The system-agnosticism of Curse does require some conversions on the fly, and those conversions will be more onerous with something like 5e than it would be with Labyrinth Lord or the like, so if your favorite engine is a bit complex, expect to have to do a little bit more work to convert Curse to it.
Still, I think that's work worth doing.
Curse treads some pretty familiar territory plotwise, but it's very well constructed. There are multiple routes through it, there's a solid and nuanced reward at the end, and the title villain's behavior and backstory makes it suitable for scaling to fit audiences of almost any age. Moreover, you can get a lot of mileage out of Curse if you give it some atmosphere. Run with minimal description, it's going to be bland---but emphasize the smell of salt water, the roll of fog, the creaking of timbers in the dark, and suddenly it's a shockingly different experience. At its most intense, it's still only spooky rather than scary, but as long as your group's not exclusively looking for something that feels like Berserk, you'll have a good time.
Overall, I would recommend Curse to anyone who plays fantasy adventure games, and especially if they've got younger players or players who are just getting into the pastime. If you've played a lot of adventures and you're looking for something novel, this isn't that and you may want to steer clear. But if you want to see a classic concept done solidly, this is absolutely one of those and you should pick up a copy.
Minor Issues:
-Page 14, 3rd para, "squeels" squeals