The listing, Mindustry (Steam Key) has ended.
https://store.steampowered.com/app/1127400/Mindustry/
About This Game
Create elaborate supply chains of conveyor belts to feed ammo into your turrets and produce materials to use for building
Use production blocks to create a wide variety of advanced materials
Defend your structures from waves of enemies
Play with your friends in cross-platform multiplayer co-op games, or challenge them in team-based PvP matches
Distribute liquids and fight constant challenges, like outbreaks of fire or enemy flier raids
Get the most out of your production by supplying optional coolant and lubricant
Produce a wide variety of units for automatic management of your base or assault on enemy bases
Campaign
Conquer the planet Serpulo as you advance through 250+ procedurally generated sectors and 16 hand-made maps
Capture territory and set up factories to produce resources while you play other sectors
Defend your sectors from periodic invasions
Coordinate resource distribution between sectors via launch pads
Research new blocks to fuel progress
Invite your friends to complete missions together
120+ technology blocks to master
33 different types of drones, mechs and ships
50+ achievements to complete
Gamemodes
Survival: Build turrets to defend from enemies in tower-defense based gameplay. Survive as long as possible, optionally launching your core to use your collected resources for research. Prepare your base for intermittent attacks from airborne bosses.
Attack: Build factories for units to destroy the enemy cores, while simultaneously defending your base from waves of enemy units. Create a variety of different types of support and offensive unit to assist you in your goals. Optionally enable an AI that builds defensive structures to an extra challenge.
PvP: Compete with other players on up to 4 different teams to destroy each other's cores. Create units, or attack other bases directly with your mechs.