Cloned Games

Free & Open Source Sci-Fi Games

489 free, open-source sci-fi games — real clones and remakes you can download, inspect the source of, and modify.

Sporadic
Oric-Software screenshot
Oric-Software

Clone of Uridium

A shared repository of Oric home-computer games, demos, tools and routines by many authors.
Platforms:Oric
Stars9
Updated8 months ago
LicenseUnknown
Release2024
Genre: Shooter
Theme: Sci-Fi
Halted
glDoom screenshot
glDoom

Clone of Doom

glDoom Resurrected continues Bruce Lewis's original OpenGL Doom source port, adding fixes, an SDL2 backend, and Windows/Linux builds.
Platforms:WindowsLinux
Stars9
Updated1 year ago
LicenseUnknown
Release2022
Genre: FPS
Theme: Sci-Fi
Active
No preview
neortcw

Clone of Return to Castle Wolfenstein

A Return to Castle Wolfenstein source port based on iortcw, with a higher tick rate, Steam file detection and a CMake build.
Platforms:WindowsLinuxOSX
Stars9
Updated2 months ago
LicenseGPL-3.0
Release2026
Genre: FPS
Theme: Sci-Fi
Archived
No preview
Alien Bash II

Clone of Alien Bash II

Platforms:Amiga
Stars8
Updated9 years ago
LicenseUnknown
Release2017
Genre: Shooter
Theme: Sci-Fi
Halted
Super Transball 2 screenshot
Super Transball 2

Clone of Zarathrusta

The third Transball game, a Thrust-style, gravity-based game where you fly a ship to retrieve a sphere across 15 levels.
Platforms:WindowsLinuxOSX
Stars8
Updated6 years ago
LicenseGPL-2.0
Release2020
Genre: Action
Theme: Sci-Fi
Halted
Xgalaga SDL screenshot
Xgalaga SDL

Clone of Galaga

An SDL port of Joe Rumsey's X11 Galaga clone, originally released as shareware before going GPL.
Platforms:Amiga
Stars8
Updated4 years ago
LicenseGPL-2.0
Release2015
Genre: Action
Theme: Sci-Fi
Halted
starshatter-open screenshot
starshatter-open

Clone of Starshatter

The Starshatter space combat simulator's source code, migrated from Google Code and released under a BSD license.
Platforms:Windows
Stars8
Updated11 years ago
LicenseUnknown
Release2015
Genre: Simulation
Theme: Sci-Fi
Halted
No preview
AB3D-RTG

Clone of Alien Breed 3D

An Amiga build of John Girvin's Alien Breed 3D source, reviving the Chunky-Copper renderer for RTG output; currently unplayable.
Platforms:Amiga
Stars7
Updated4 years ago
LicenseUnknown
Release2021
Genre: FPS
Theme: Horror
Sporadic
Galaga500 screenshot
Galaga500

Clone of Galaga

Transcodes the original Z80 arcade code to 68K assembly for the Amiga, fully playable with sound at 25–50 FPS depending on hardware.
Platforms:Amiga
Stars7
Updated3 months ago
LicenseUnknown
Release2023
Genre: Action
Theme: Sci-Fi
Sporadic
SuperStarTrek25thGMS screenshot
SuperStarTrek25thGMS

Clone of Super Star Trek

A Game Maker Studio remake of the Adventure Game Studio fan game Super Star Trek Meets 25th Anniversary.
Platforms:Android
Stars7
Updated5 months ago
LicenseUnknown
Release2025
Genre: Simulation
Theme: Sci-Fi
Halted
No preview
TINY TREK

Clone of Tiny Trek

A remake of Tiny Trek for the Playdate handheld, played using the device's crank and A/B buttons.
Platforms:Playdate
Stars7
Updated3 years ago
LicenseUnknown
Release2022
Genre: Simulation
Theme: Sci-Fi
Active
No preview
TekwarGDX

Clone of TekWar

Platforms:None
Stars7
Updated2 months ago
LicenseUnknown
Release2018
Genre: FPS
Theme: Sci-Fi
Sporadic
No preview
TimeCo

Clone of Time Commando

An early-stage, not-yet-playable engine reimplementation of the 1996 Adeline Software game Time Commando.
Platforms:LinuxOSX
Stars7
Updated4 months ago
LicenseGPL-2.0
Release2024
Genre: Action
Theme: Sci-Fi
Halted
No preview
star-control2

Clone of Star Control 2

A Windows remake of Star Control 2, built by combining the author's own custom engine, input, and ECS systems.
Platforms:Windows
Stars7
Updated7 years ago
LicenseMIT
Release2016
Genre: Adventure
Theme: Sci-Fi
Halted
Alien Breed 3D I screenshot
Alien Breed 3D I

Clone of Alien Breed 3D

A rebuild of Alien Breed 3D I for AGA Amiga from the original source, requiring original data files; playable, but development has halted.
Platforms:Amiga
Stars6
Updated1 year ago
LicenseUnknown
Release2023
Genre: FPS
Theme: Horror
Halted
EXLCOM screenshot
EXLCOM

Clone of X-COM: UFO Defense

Platforms:Excel
Stars6
Updated2 years ago
LicenseUnknown
Release2023
Genre: Strategy
Theme: Horror
Halted
No preview
Inertia Blast

Clone of Thrust

An SDL-based clone of Thrust, originally an MS-DOS game by Peter Ekberg, now maintained by Dennis Payne for Windows and Linux under GPL2+.
Platforms:WindowsLinux
Stars6
Updated1 year ago
LicenseGPL-2.0
Release2021
Genre: Arcade
Theme: Sci-Fi
Halted
Quake II for Dreamcast screenshot
Quake II for Dreamcast

Clone of Quake 2

An unofficial, software-rendered Dreamcast port of Quake II, running from demo or full commercial game data.
Platforms:Dreamcast
Stars6
Updated4 years ago
LicenseGPL-2.0
Release2021
Genre: FPS
Theme: Sci-Fi
Halted
Sea Defender screenshot
Sea Defender

Clone of Missile Command

A minimalist, about 96KB clone of Missile Command for Linux, Windows, and macOS, made for a demoscene competition.
Platforms:WindowsLinuxOSX
Stars6
Updated16 years ago
LicenseMIT
Release2010
Genre: Arcade
Theme: Sci-Fi
Halted
Spacewars screenshot
Spacewars

Clone of Spacewar!

A solo-built Rust/Amethyst remake of 1962's Spacewar!, made to learn the engine and language.
Platforms:WindowsLinux
Stars6
Updated6 years ago
LicenseGPL-3.0
Release2020
Genre: Action
Theme: Sci-Fi
Active
No preview
Starfox 64: Recompiled

Clone of Star Fox 64

A fork of the Star Fox 64 recompilation project adding Universal Windows Platform (UWP) support.
Platforms:WindowsLinuxOSX
Stars6
Updated1 month ago
LicenseUnknown
Release2025
Genre: Shooter
Theme: Sci-Fi
Archived
No preview
TekWar

Clone of TekWar

Platforms:DOS
Stars6
Updated1 year ago
LicenseUnknown
Release2025
Genre: FPS
Theme: Sci-Fi
Sporadic
No preview
TriSpace

Clone of Elite

An Elite-like space game for the FunKey S handheld, with procedurally generated star systems, combat, and ship upgrades.
Platforms:Linux
Stars6
Updated8 months ago
LicenseAGPL-3.0
Release2021
Genre: Action
Theme: Sci-Fi
Halted
No preview
jedi_outcast

Clone of Star Wars Jedi Knight II: Jedi Outcast

Raven Software and Activision's official 2002 GPLv2 source release of Jedi Knight II: Jedi Outcast, not a third-party reimplementation.
Platforms:Windows
Stars6
Updated13 years ago
LicenseGPL-2.0
Release2013
Genre: Fighting
Theme: Fantasy
Halted
No preview
mm4

Clone of Mega Man 4

A nearly complete disassembly of Mega Man 4 (US) that reassembles to a byte-identical NES ROM.
Platforms:NES
Stars6
Updated3 years ago
LicenseUnknown
Release2023
Genre: Platform
Theme: Sci-Fi
Halted
Breach for Genesis screenshot
Breach for Genesis

Clone of Breach

A port of the Amiga tactical game Breach to the Sega Genesis in 68000 assembly, with tools to convert Amiga level data and a level editor.
Platforms:Genesis
Stars5
Updated6 years ago
LicenseUnknown
Release2020
Genre: Strategy
Theme: Sci-Fi
Active
No preview
Megaman3NESRecomp

Clone of Mega Man 3

A static recompilation of Mega Man 3 (NES) into a native PC executable; an in-development preview where boss fights remain untested.
Platforms:WindowsLinuxOSX
Stars5
Updated17 days ago
LicenseUnknown
Release2026
Genre: Platform
Theme: Sci-Fi
Halted
No preview
Phantasy Star II Disassembly

Clone of Phantasy Star II

A disassembly of Sega's Phantasy Star II for the Mega Drive/Genesis.
Platforms:Genesis
Stars5
Updated8 years ago
LicenseUnknown
Release2018
Genre: RPG
Theme: Sci-Fi
Halted
No preview
Phantasy Star IV Disassembly

Clone of Phantasy Star IV

A disassembly of Sega's Phantasy Star IV: The End of the Millennium for the Mega Drive/Genesis.
Platforms:Genesis
Stars5
Updated3 years ago
LicenseUnknown
Release2016
Genre: RPG
Theme: Sci-Fi
Halted
No preview
Team-47-GoMan

Clone of Team 47 GoMan

The recovered DirectX-era source code and engine for 47-TEK's 3D fighting game Team 47 GoMan.
Platforms:Windows
Stars5
Updated4 years ago
LicenseUnknown
Release2022
Genre: TPS
Theme: Sci-Fi
Halted
No preview
EXILE

Clone of Exile

A Windows remake of Exile whose development has halted, leaving the project currently unplayable.
Platforms:Windows
Stars4
Updated16 years ago
LicenseZlib
Release2010
Genre: Action
Theme: Sci-Fi
Halted
No preview
GL Quake II on Wayland

Clone of Quake 2

A port of GL Quake II to run under Wayland on the Nemo platform, with no further detail given beyond its name.
Platforms:Linux
Stars4
Updated7 years ago
LicenseUnknown
Release2018
Genre: FPS
Theme: Sci-Fi
Sporadic
No preview
NakedLinuxDoom

Clone of Doom

The Linux Doom source converted to SDL3 and 64-bit, with no other changes, for macOS, Linux and Windows.
Platforms:WindowsLinuxOSX
Stars4
Updated7 months ago
LicenseMIT
Release2025
Genre: FPS
Theme: Sci-Fi
Halted
Nether Earth Remake screenshot
Nether Earth Remake

Clone of Nether Earth

A PC remake of the 1987 strategy game Nether Earth, packaged here for Linux.
Platforms:WindowsLinuxOSX
Stars4
Updated7 years ago
LicenseUnknown
Release2019
Genre: Strategy
Theme: Sci-Fi
Halted
No preview
Vectrex-Minestorm

Clone of Mine Storm

A remake of the game Mine Storm for the Vectrex console.
Platforms:Vectrex
Stars4
Updated4 years ago
LicenseUnknown
Release2021
Genre: Arcade
Theme: Sci-Fi
Halted
Xenowar screenshot
Xenowar

Clone of X-COM: UFO Defense

A turn-based strategy game for Win32 and Android inspired by the classic X-COM series.
Platforms:OSXAndroidiOS
Stars4
Updated4 years ago
LicenseUnknown
Release2022
Genre: Strategy
Theme: Horror
Archived
allegro blasteroids screenshot
allegro blasteroids

Clone of Blasteroids

A simple Allegro5-based asteroids shooter with continuously spawning asteroids, built via CMake with only Allegro5 as a dependency.
Platforms:Linux
Stars4
Updated6 months ago
LicenseUnknown
Release2018
Genre: Action
Theme: Sci-Fi
Halted
FFED3D screenshot
FFED3D

Clone of Elite III

Platforms:Windows
Stars3
Updated10 years ago
LicenseUnknown
Release2016
Genre: Action
Theme: Sci-Fi
Halted
No preview
Phantasy Star Disassembly

Clone of Phantasy Star

A disassembly of Sega's 1987 Master System RPG Phantasy Star, for educational use.
Platforms:Master System
Stars3
Updated7 years ago
LicenseUnknown
Release2020
Genre: RPG
Theme: Sci-Fi

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