From The Depths v1.752

http://fromthedepthsgame.com/
http://store.steampowered.com/app/268650/

In From the Depths you can build and take first-person command of battleships, planes, submarines, space ships, hot air balloons and more! The game is currently in alpha and contains a wide range of single player content including:

A creative mode allowing you to push your designs to the limit and ensure the total annihilation of your opponents.
A campaign waged over hundreds of islands against eight unique factions.
A Story Mode where you can (eventually!) play 15 missions as each of the eight factions - a fantastic mixture of strategy, design and wild battles! Defend your fleet against waves of enemy forces in a series of extremely tough challenges that unlock new components.
An expansive multiplayer and co-op element is planned for the coming months!

Features:
A huge game world explorable from the ocean depths into outer space.
A full and accurate physics model including dynamic damage simulation, sailing mechanics and weather effects.
Battle against fleets of AI craft and build your own to meet the menace.
Build fortress bases, mine for resources and battle other factions in campaign mode where strength and diplomacy are the keys to victory.
In-game Steam workshop support to share your creations with the world.
RPG-Style character progression with levels, perks, skills and inventory systems.
Comprehensive in-game planet, campaign, mission and multiplayer map editor.
Available now on PC, Mac and Linux.