Free & Open Source Sci-Fi Games
521 free, open-source sci-fi games — real clones and remakes you can download, inspect the source of, and modify.
Active
Clone of Elite
This is the annotated original 6502 assembly source for the Apple II version of Elite, assembling into five byte-accurate variants.
Active
Clone of Paradroid
FreedroidClassic is a GPL-licensed remake of Paradroid, with some improvements and extensions, for Windows and Linux.
Halted
Original game image
Original game imageClone of Space Ace
A reverse-engineered rebuild of the 1990 Apple IIgs port of Space Ace, rewritten to run from a hard disk instead of floppy disks.
Archived
Active
Clone of Elite
The original 1985 BBC Micro assembly source for Elite, documented by Mark Moxon and buildable into byte-accurate historical discs.
Active
Clone of Quake 3
A free arena FPS with a macabre sci-fi theme and 23 levels; its engine is GPL-licensed and actively developed for Linux and Windows.
Halted
Original game image
Original game imageClone of Aliens Versus Predator
The released Windows source for Aliens versus Predator Gold, mirrored from a 2008 GameFront download; development here has halted.
Halted
Clone of Atomic Robo-Kid
The original Commodore 64 conversion source for Atomic Robo-Kid, released by its own developer from his personal backups.
Halted
Active
Clone of Phantasy Star
JLud2D, a 2D engine once a Java desktop app, is being ported to TypeScript and Phaser 3 for browser demos like a Phantasy Star RPG remake.
Halted
Clone of MechWarrior
Platforms:WindowsLinux
Stars38
Updated3 years ago
LicenseApache-2.0
Release2012
Genre: Simulation
Theme: Sci-Fi
Halted
Clone of In Pursuit of Greed
A Windows source port of the 1995 DOS shooter In Pursuit of Greed, adding mouse-look and higher resolution.
Halted
Clone of Wipeout
CoreBreach is an anti-gravity combat racer built on the open-source Core3D engine, targeting Linux, Windows, macOS and Android.
Halted
Clone of Might and Magic IV: Clouds of Xeen
An unfinished Java rewrite of the Might and Magic: World of Xeen engine with planned gameplay changes.
Active
Clone of AeroGauge
A PC version of the N64 racer AeroGauge for Windows, Linux and Android that runs your own ROM natively.
Archived
Halted
Original game image
Original game imageClone of Mega Man 5
A finished disassembly of the NES game Mega Man 5 (NTSC-U) that assembles to a clean ROM.
HaltedOriginal game image
Original game imageClone of Mega Man 5
A complete disassembly of the NTSC-U Mega Man 5 (NES) ROM that reassembles byte-for-byte via the bundled xkas-plus build.
Active
Clone of Elite
A fully documented, hand-reconstructed disassembly of Elite for the Acorn Electron, buildable into disc or tape images.
Sporadic
Halted
Original game image
Original game imageClone of Carrier Command
An open-source futuristic flight-sim/action game inspired by the 1988 vehicle-sim classic Carrier Command.
Platforms:OSX
Stars33
Updated2 years ago
LicenseUnknown
Release2010
Genre: Real-Time Strategy
Theme: Sci-Fi
Active
Clone of Elite
Ian Bell and David Braben's 1986 Acornsoft Elite source for the BBC Master, hand-reconstructed and documented by Mark Moxon.
Halted
Original game image
Original game imageClone of Oo-Topos
Re-Comprehend is a public-domain reimplementation of the Graphics Magician engine behind Transylvania, Crimson Crown, and Oo-Topos.
Halted
Clone of Super Star Trek
Faithful Perl and Lua ports of the 1978 BASIC-published Super Star Trek game by Mike Mayfield and Bob Leedom.
Halted
Clone of Master of Orion
1oom is a from-scratch, GPLv2 engine recreation of Master of Orion (1993), requiring the original game's data files to run.
Platforms:WindowsLinuxDOS
Stars31
Updated3 years ago
Licensegpl-2.0+
Release2018
Genre: Turn-Based Strategy
Theme: Sci-Fi
Halted
Original game image
Original game imageClone of Star Trek: Voyager – Elite Force
Elite Reinforce is a source port of Star Trek: Voyager – Elite Force's singleplayer campaign, focused on bugfixes and speedrunning.
Halted
Clone of MechCommander 2
MechCommander 2 Omnitech is a mod building an upgraded, more moddable version of MechCommander 2 from Microsoft's Shared Source release.
Platforms:Windows
Stars31
Updated13 years ago
LicenseUnknown
Release2012
Genre: Real-Time Tactics
Theme: Sci-Fi
Halted
Clone of The Bilestoad
This repository preserves The Bilestoad's original Apple II source code as unconverted floppy disk images, not a ready-to-run build.
Sporadic
Clone of Doom 64
This is a from-scratch Dreamcast port of Doom 64, built on KallistiOS and requiring the original game's data to run.
Halted
Original game image
Original game imageClone of Mega Man 4
A complete NES disassembly of Mega Man 4 (NTSC-U) that assembles to a clean ROM.
HaltedOriginal game image
Original game imageClone of Mega Man 4
A complete disassembly of the NTSC-U Mega Man 4 (NES) ROM that reassembles to a byte-for-byte clean ROM, though not all code is documented.
Sporadic
Original game image
Original game imageClone of Master of Orion 2
An early open-source remake of Master of Orion II that can currently load and view original savegames.
Platforms:WindowsLinux
Stars29
Updated11 months ago
LicenseGPL-2.0
Release2021
Genre: Turn-Based Strategy
Theme: Sci-Fi
Sporadic
Original game image
Original game imageClone of AeroGauge
An early-stage N64 decompilation project reconstructing AeroGauge's source code, requiring a legitimate ROM to build.
Halted
Sporadic
Original game image
Original game imageClone of Exile
A buildable reconstruction of the BBC Micro game Exile that produces disk images matching the original byte-for-byte, verified by SHA1.
Halted
Original game image
Original game imageClone of StarCraft
Magnetar is a StarCraft mod that loads the original StarCraft.exe into memory and combines it with its own additions.
Platforms:Windows
Stars28
Updated2 years ago
LicenseMIT
Release2016
Genre: Real-Time Strategy
Theme: Sci-Fi
Sporadic
Original game image
Original game imageClone of TekWar
A port of William Shatner's TekWar built on a port of the Build engine, run with data from an original release.
Active
Active
Clone of Star Wars: Shadows of the Empire
A playable Windows open-beta static recompilation of the N64 Star Wars: Shadows of the Empire, built with N64Recomp.
Stars25
Updated1 month ago
LicenseUnknown
Release2026
Genre: Action
Theme: Sci-Fi