The player will take the lead of one of the three factions, each with its individual characteristics, strengths, weaknesses, technologies and special skills, such as climate control, espionage and precognition.

During the missions, you will have to manage your resources, expand your colonies and extend your control of the map to assemble an army capable of crushing your opponents. Epic battles will ensue between formidable armies comprising numerous units that vary depending on the faction, each having its strengths and weaknesses: infantry, all types of tank, naval units and gigantic colossi of war several meters high; real machines of destruction!

You will also use scientific research to develop a tech tree enabling you to unlock new units and upgrades, access new structures to develop your colony and to use new special skills.

In Conquest mode, a real galactic conquest awaits you. In this entirely non-linear mode, plan your tactics in turn-based, building invasion fleets, developing your technology tree to unlock new units and skills, spying on the enemy and sabotaging them, and ultimately invading their territories and planets in real-time strategy battles! You are free to decide how your conquests progress. Manage your resources, expand your colonies and extend your control of the map to assemble an army capable of crushing your opponents.

When invading an enemy planet or territory, you are sent to real-time strategy mode, where epic battles will ensue between formidable armies comprising numerous units: infantry, tanks, aircraft, and even gigantic colossi of war several dozens of meters high; real machines of destruction! Technological advancements made during turn-based view will let you use increasingly more powerful or specialized units: use scientific research to develop a tech tree enabling you to unlock new units and upgrades, access new structures to develop your colony and to use new special skills.

Etherium has a unique and dynamic weather control system that has a direct impact on the player's gameplay and strategy. You can use a sandstorm to approach the enemy base unseen, or mount a rearguard attack crossing a freezing river with your tanks. This weather control system will also work through synergy with the special skills of the factions. For example, one of the empires may create localized weather conditions, to help its army, or hamper the opponent's forces. Another faction will have the ability to see into the future to predict where and when the next climatic events will occur, and devise a strategy based on future events.

The solo campaign in Etherium is non-linear, so you are free to decide how your conquests progress: you can choose which of the planet's continents or moons will provide the setting for your next mission. It may be more advantageous to conquer particular territories, but these may also be better defended. You will also have to stop the enemy from recapturing territories you have gained! Every continent and moon has very diverse environments, and varied terrain that will force you to adapt your strategy and employ different tactics: arid desert, jungles and swamps that impede the advance of the tanks, icy worlds, island archipelagos... you must consider the terrain very carefully before implementing your strategy! You will also encounter six secondary factions during the campaign (raiders, alien beings, etc). You could of course fight them, but alternatively you could also rally them to your cause, to exploit their units and special skills!

Finally, Etherium will also test the strategic skills of every player in online modes, where up to four players can compete simultaneously.