R.E.P.O. Portal Gun

Experimental version 0.1.1 for R.E.P.O. 0.4.4.3 (Windows/Steam).

Bring a physical portal gun to R.E.P.O.: open a blue portal and an orange one and walk through them while keeping your momentum. Each player has their own pair, and everyone can use every pair. Views show the other end, and objects carry their motion and spin through.

What's included

• One starting gun per player, plus extra copies available in the shop; whether they show up depends on the shop's normal selection and budget.
• Teleportation for the player, loose objects, and held objects, with momentum and throws between floor, wall, and ceiling.
• Portals on static, flat, sufficiently large surfaces; obstructions are rejected with a visible indicator.
• Fire from the crosshair even when the gun itself is touching the wall.
• Default controls are Q (blue), E (orange), R (clear), and can be remapped in Settings > Controls in-game.

Requirements and installation

All you need is your copy of R.E.P.O.; Portal 2 is an inspiration, not a requirement. No Portal 2 files or assets are included. The recipe requires BepInEx 5.4.23.5, which Melty installs automatically, and includes REPOLib 4.2.0 along with its license. No game files are distributed.

Playing solo or with friends

Only tested on an isolated copy of the game. Co-op syncing is implemented, but this version has no real two-client test. Everyone must use exactly this version and REPOLib. To try it with friends, use R.E.P.O.'s private lobbies and normal invites; joining is done in-game. The game allows up to 20 players in its settings (6 by default); that capacity is not proof that the mod works with 20 players.

Testing and limits

Verified: real Q/E shots with the gun against a wall, the native controls menu and binding persistence, rendering, player teleportation and momentum, loose and held objects, and shop purchase eligibility. 33 logic tests and 11 design sheet tests passed. Still pending: a co-op session between two machines, a full shop purchase, persistence across an entire run, and broad compatibility with other mods. There are no recursive views or rendering of objects split between portals. Installation through Melty's Test button is still pending.

The screenshots are from exactly 0.1.1: the first shows a controlled test scene inside R.E.P.O.; the second shows all three actions in the native menu. They are not a full walkthrough of a normal map.

Credits

Created with help from OpenAI Codex (GPT-6 family) and the Universal Modder toolkit. BepInEx, Harmony, and REPOLib belong to their respective authors; third-party notices are included. The weapon model and portal edges are original and procedural; no art or audio was generated with fal. R.E.P.O. belongs to semiwork; inspired by Valve's portal mechanic. Unofficial project.

The license for the original content is still pending confirmation from the creator. Remixes are allowed on Melty with attribution to the original project, keeping third-party credits and licenses intact. This does not replace a separate license for the code. Unpublished draft.