Games like Defcon 5

Allegiance is a multiplayer space combat sim originally developed by Microsoft that offers the action of ship-to-ship combat. From small, agile scouts to massive destroyers, you not only fly but also man the turrets. With real-time strategy components such as fully upgradeable tech and massive multiplayer capability, Allegiance stands at the forefront of online interstellar combat.

Genesis Alpha One is a first-person shooter and base-building game set in space. Players must build and upgrade their spaceship, recruit crew members, and fight off alien threats while searching for a new home for humanity. The game also includes survival and roguelike elements, with procedurally generated levels and permadeath.

"Sentry" is a Science Fiction Shooter game that offers various play options, including single-player, co-op for 2 players, and multi-player. As a member of the SENTRY Defense Program, your mission is to protect your vessel while it flees across space, using an arsenal of weapons, traps, and environmental destruction to fend off alien boarders. If your SENTRY falls in battle, another crew member will be thawed to continue the fight, ensuring that defeat only changes the strategic landscape aboard the ship. The game boasts beautiful gameplay and outstanding visuals.

"PULSAR: Lost Colony" is a sci-fi cooperative game where players take on roles such as captain, pilot, engineer, and weapons specialist to operate a space ship and complete missions. The game supports both single-player and multiplayer modes, with up to five players able to join forces in online play. Players will encounter various alien species, challenging space environments, and must manage resources and make strategic decisions to survive.

B3 will be a first-person VR shooter where you have to defend your base from waves of attacking monsters. The base is protected from the back and sides by mountains. On the front side, it has a wall with firing points. To protect the base, you need to move all around these points, using a teleport system. So, when you need to go to another point, you look at the flag above it and instantly telep…

Xenopurge is a single-player science fiction real-time strategy game where you command an elite squad remotely through multiple screens, directing tactical auto-battles against relentless alien forces. Emphasizing anticipation and planning over direct control, it features wonderful game mechanics and an exceptional atmosphere as you manage gear, strategies, and sacrifices to purge the Xeno threat.

In "Nimbatus: The Space Drone Constructor," you are the captain of a mobile drone factory, where you can design and build your own custom drones using over 75 physically simulated parts. Explore a physics-based universe in three different game modes: a survival campaign, sandbox mode with adjustable parameters, and competitive arenas to show off your engineering skills. Confront challenging enemies and obstacles or focus on creative freedom.

"Hexen: Beyond Heretic" is a fantasy-themed first-person shooter game that transports players to a dark and mystical world filled with monsters and magic. As a powerful sorcerer, players must navigate through complex levels, defeat hordes of enemies, and solve puzzles to progress through the story. Featuring a variety of weapons, spells, and abilities, players can customize their playstyle to suit their preferences to defeat the ultimate evil threatening the realm.

Foresight is an epic space-based RTS game that throws you, the player, into the thick of the battle as a commander. Lead huge fleets, armed with fighters and bombers across wormholes to fight it out with your enemy. Launch bombing missions, fighter patrols, plant observation posts or fire support base with reconnaissance units. Intelligence is key.

X4: Foundations is a sandbox space simulator that allows players to explore, trade, fight, and build in a vast universe. Take control of your own space empire, where every decision from ship hiring to trade routes has a direct impact on your income and influence. With a dynamic narrative and a variety of factions to interact with, X4: Foundations offers a rich and immersive space experience.