Matthew Hartley has a game called Kraken, inspired by the man against sea monster scene in Jules Verne’s 20,000 Leagues Beneath the Sea
Rules: Steampunk
Cloudships Of Mars
Cloudships of Mars is a set of free wargames rules based on the excellent Space: 1889 universe. The Cloudships game features ships propelled by steam and sail gliding high above the plains of Mars thanks to the magic of “Liftwood.”
Timeline 300 Steampunk Rules
Timeline 300 is a set of steam-punkish rules for a now-defunct line of miniatures. The rules, though, can be applied to other figures.
Castles In The Sky Aerial Battleship Rules
Castles In The Sky is a set of free wargames rules for flying battleships. The author writes:
In these pages you will find a game that allows you to play out aerial battles between flying battleships fighting in a mythical turn-of-the-century world. The War of the Worlds is over, but the World Wars are just beginning. You will take command of these massive, armored, battleships in the skies around the world! Your commands will lead your forces to glorious victory or disgraceful defeat. The fate of nations depends on you!
Malifaux 2nd Edition Rules
The second edition Maifaux Rules are available free for the downloading.