Clamdash! is a clever one page Mork Borg scenario with a tight premise and some fun, lighthearted (well, sorta) adventuring.
The basic premise is that a rare clam dungeon has just recently unflooded, and if you gather enough clams you can earn an audience with Anthelia. This is a nice mix between approachable and system-neutral and specific and hooked into the Mork Borg metaplot, and it's just as easy to drop Clamdash into a campaign as it is to run it as a one-off.
The layout is what you'd expect for a Mork Borg game. It's intricate and dense, but everything is readable despite that. There's a lot of contrast used to make the text pop, and the background and dungeon map are both nice pieces of art.
Mechanics-wise, Clamdash is clever. The dungeon is constantly re-flooding, and each chamber has markers to track how high its water level is. The longer you spend mucking about, the more the dungeon floods. The more the dungeon floods, the more dangerous its deeper rooms become. This underlying push-your-luck mechanic feels neat, but the dungeon itself is solidly build as well. There's a variety of ways to progress, the monsters all have unique builds and personality, there's options for backup PCs, and the rewards are good if the party does manage to thread the needle on filling their clam buckets without being flooded out.
Overall, if you're looking for an osr oneshot, I'd strongly consider this. It's fun, it's an interesting challenge, and it's quite flavorful.