#3 StarForge
Not to be confused with the “Star Forge” of Knights of the Old Republic fame, StarForge is a construction-focused game that’s also a first-person shooter and a tower defense game. You must gather resources, build a base, and survive on an alien planet hostile to human life.
In StarForge, you’ll have the opportunity to construct a base by digging trenches, erecting towers, and building all manner of defenses. Additionally, you can alter the terrain and mine for a variety of resources which you can use to construct your base and craft items. Speaking of which, the sky’s the limit with what you want to build, as StarForge even supports an atmosphere above the planet.
Finally, StarForge also comes with a competitive multiplayer mode called Fort Wars which invites teams of players to construct forts and do battle with each other.