Defcon 5

Defend a futuristic base, control turrets and hack systems in a tense first‑person sci‑fi shooter.

gameFirst-Person Shootersshootersimulatoradventure

Alternatives

Mazer

In Mazer, players select one of four elite soldiers to liberate Earth from the tyrannical alien race known as the Semag-Resal. Their sprawling network of bases and perfect‑mimic cyborg spies create a tense battlefield where every decision matters.

✦ Best for retro sci‑fi shooter fans craving atmospheric horror and character variety

Paid (One-time)ProprietaryPCCharacter-SelectionAlien-EnemiesCyborg-Infiltration

“Battles alien forces across multiple bases, aligning with Mazer's base‑centric shooter gameplay.”

Marathon

AI-suggested

Set in the distant future aboard the colony ship UESC Marathon, you play as a security officer tasked with protecting humanity’s first interstellar outpost.

✦ Best for retro shooter fans craving deep sci‑fi story and modding

Paid (One-time)ProprietaryiOSMacSingle-player campaignMultiplayer modeSci-fi setting

“First‑person sci‑fi shooter focused on defending a futuristic base, sharing Marathon's FPS combat and setting.”

Xenocide

AI-suggested

Xenocide thrusts players into a hostile alien environment where tactical shooting meets deep simulation. Explore sprawling landscapes, manage resources, and uncover the mystery behind the extraterrestrial threat.

✦ Best for retro sci-fi shooter fans

Paid (One-time)ProprietaryPCRetro GraphicsResource ManagementProcedural Levels