Note
A special thank you to Thomu, Moro, and JMOTZU for their extensive playtesting in the Co-op mod. Also, a special thank you to Thomu for his generous support towards the project's development.
X and Zero. Together.
Mega Man X4 on Windows and Linux. 1.0.2 Stable Public Beta, with two-player co-op. Bring a friend through X's or Zero's campaign, on one computer or over netplay.
Downloads · What's new in 1.0.2 · Known issues
Play X and Zero simultaneously, with their own attacks, voices and effects. Player 1 owns the story, boss clears and permanent progress; Player 2 joins as the other hero. Arrive together, tackle bosses together, and share team retries.
| Make it your co-op run | Choices |
|---|---|
| Play together | Local co-op with two controllers or separate keyboard bindings; two-player netplay from the launcher. |
| Pick your view | Unified camera by default. Split (Experimental) gives each netplay player an independent screen. Local co-op also offers side by side 8:3 (Experimental), with two 4:3 views in one window. |
| Arrange your HUD | Stacked lifebars by default, or side by side. Independent screens show their own player's meter. |
| Manage your supplies | Either player opens both heroes' own pause menus. Choose weapons and manage supplies independently; either player resumes both. E-tank energy is separate while independent menus are enabled, and healing blocks unpause while your partner can keep navigating. |
| Set the door rule | Either player opens boss doors by default. Optionally wait for both living, present players. |
| Fight both story bosses | Opt into Double and Iris in sequence; return to the inner door for the second fight. |
| Turn up the challenge | Optional double effective boss health and shorter hit cooldowns, with separate timers for each player or one shared timer. Scaling also reduces Zero's boss damage by 20%. |
| Enable the secret codes | Ultimate Armor X's code and Black Zero can be enabled together. X still needs a capsule for the armor. |
The extra boss encounters, scaling and character codes are off by default. The netplay host chooses the shared options.
One shared world, two independent netplay views. Split remains experimental.
Double and Iris in one co-op run, when you enable the option.
- Download the Windows ZIP and extract it. The 1.0.2 Linux AppImage is pending; earlier AppImages require x86_64 and glibc 2.38 or newer.
- Select your own Mega Man X4 USA (SLUS-00561) disc image. Choose the
.cuefrom a.cue+.binset. OpenBIOS is included; a separate BIOS dump is optional. - For local co-op, enable Mods → X + Zero Co-op, assign Player 1 and Player 2 in Controls, and choose Local co-op display for Unified or side by side 8:3, then press Play. For netplay, press Netplay and host or join using X + Zero Co-op. Both peers need the same release.
Co-op requires OpenGL and takes effect on a fresh game boot. Single-player remains available.
Fast loading is built in. The old CD Speed and Fast Loading mods are retired; the game now keeps verified disc data in memory and feeds it through the original loading routines. Music and cutscenes retain their normal timing.
Offline co-op also supports save states (F7) and rewind (F8) when enabled. The Mods page includes widescreen, character codes and optional input display and diagnostic recording, off by default. Controls, saves and reporting guide →
Optional language mods offer Spanish and Brazilian Portuguese dialogue using the game's own font. Supply your Japanese Rockman X4 disc to choose Japanese movies, voices and the title screen independently. Translations are drafts awaiting native-speaker review. Language setup and scope →
See the co-op settings
Expect bugs; independent cameras can still slow down. Online sign-in/startup reports remain under investigation. Check the burndown or report a bug.
To record a bug, enable Playtest Diagnostics → Input Display and Recording
before local play. For netplay, the host enables X + Zero Co-op → Netplay
diagnostic recording for both peers. Both recording options default off.
Reproduce the problem, quit normally,
and zip saves/diagnostics beside the executable or AppImage. Include a video
and the release version; for netplay, collect both computers' logs. These
recordings include starting game saves. Details →
Built with PSXRecomp and recomp-ui. Build and contribute · R.A.I.D. community
Original project code is MIT licensed. Dependencies retain their own licenses and notices. Mega Man X4 and the game imagery belong to Capcom. You supply the game disc; this is an unofficial project.