Interplanetary is a turn-based strategy artillery game based on a hard scifi setting. It offers players an interplanetary battlefield where they can develop their home planets and use massive artilleries to wage war.

It’s an arms race of interplanetary scale, with each planet developing increasingly powerful railguns, missiles and even beam weapons. Sometimes, the greatest foe is the unpredictable planetary system with its treacherous gravity wells. Mind your surroundings, use them to your advantage and blast your enemies back to the stone age.

http://store.steampowered.com/app/650220/
The original Interplanetary is no longer on sale. Instead, you can purchase the improved version—
Interplanetary Enhanced Edition
Interplanetary is a turn-based strategy artillery game based on a hard scifi setting. It offers players an interplanetary battlefield where they can develop their home planets and use massive artilleries to wage war.
It’s an arms race of interplanetary scale, with each planet developing increasingly powerful weapons. Massive railgun batteries are the backbone of any interplanetary arsenal, but the cunning use of missiles and precision lasers may hold the key to victory. Strategic building patterns, upgrades and defense structures might keep your vital installations standing long enough to give you an edge, but it’s only a matter of time until all but one must fall.

Interplanetary Key Features:
1, Challenge your friends in hotseat or online matches or fight skirmishes against the AI.
2, Build and manage your planet’s infrastructure.
3, Gather resources and decide the most efficient use for them.
4, Research and develop increasingly futuristic technologies.
5, Spy on your enemies to reveal their planets’ weak points.
6, Use your artillery constructions to aim across the planetary system, avoiding other celestial bodies and their gravity.
7, Fire your railguns, missiles and beam weapons to annihilate the enemy and claim the planetary system for your civilization!