Harper's Quest is an osr dungeon-crawler aimed at delivering an easy-to-learn, low prep delving experience.
The PDF is 9 pages, with neat custom art in full color.
The book gets right to the meat of what it's about with no preamble, but the layout organizes everything in a way that makes it super easy to read.
Game setup takes minutes. You roll up a number of dungeon rooms, then some random stats. The damage that you deal is controlled by a difficulty toggle (set the game on easy and deal more damage per hit,) and the frequency of dungeon encounters can similarly be customized.
There's a small slate of flavorful random encounters, and there's variety to the individual bosses and creature fights that you can cross paths with as well.
There's also a neat roguelike twist, in that if your character dies, their successor gets a share of their stuff.
If you haven't played an rpg before, you might be a little confused with Harper's Quest. That said, it should otherwise be quick to pick up.
Overall, this is a great pocket system. It's extremely lightweight, but not without that familiar crunch, and there's a free published adventure for it (Castle of Chronos, link above) as well. If you're looking to dungeon-dive at the drop of a hat, this is definitely a game you should check out.
Minor Issues:
-The first page being a spread of all the pages in the book feels a little strange. I don't think it's a problem, but also I had a moment of "did I open the wrong PDF" on encountering it.
-Is there one new door per room? I couldn't figure out if there was a formula for generating how many doors, rather than which type of door.
-I didn't see anywhere other than the last page that referenced heirlooms. I love the idea, I just wasn't sure what it pointed to.