Sunless Skies, the follow up after Sunless Sea from Failbetter Games, now has a free tabletop RPG called Skyfarer that you can download from Tabletop Gaming.
After perusing through the rules, I can say that the game is more Dungeon World than Dungeons & Dragons. It is more concerned with telling interesting stories between players than it is with giving you a crunchy set of rules, deep combat encounters, or specific dice rolls that need to be made for every kind of action.
In both Sunless Seas and Skies, the player takes control of a Captain who makes all of the decisions in the game. Skyfarer moves away from that model in order to turn the players into the crew of a ship. It is a conceit of the game that the Captain can no longer make decisions, so the crew is tasked with completing some strange task that Captain is driven to, but unable to, accomplish.
The player who takes on the role of the Gamesmaster (the game's equivalent of a Dungeon Master) then helps guide players through the weird universe of steampunk spaceships.
The game asks players to think seriously about their characters and the relationships that those characters have to their craft. In a unique move, players must name the engine of their ship and pick qualities for it, and some gameplay functions depend on the operation of that shift.
From reading the rules, I would suggest that this is best played with a group of experienced players, or at least a Gamesmaster who is pretty familiar with tabletop RPGs. There are not a lot of hooks here for how to actually run a campaign from moment to moment, although the suggested plot hooks and basic roll resolution mechanics are quite good. A less experienced GM might... run aground... without having some basic methods for keeping interest alive and action constant.