SS2 Revive

SS2 Revive brings Surgeon Simulator 2 back online. It restores multiplayer, voice and text chat, progression, Creation Mode, and community-made levels after the original online services shut down.

The mod answers the retired service calls locally, carries multiplayer traffic over Steam, and reconnects the in-game level browser to an independently operated community catalogue. Your progression and levels stay on your own computer. This repository distributes no original game code and no game assets.

Current release	1.2.1 — download the installer
Supported game build	Surgeon Simulator 2 1.3.7.3054
Platform	Windows x64, with Steam running
Not supported	Game version 1.5.x, which removed the networking implementation this project restores

Unofficial fan project. SS2 Revive is not affiliated with Bossa Studios or Curve Games. See License and disclaimer.

What SS2 Revive restores

Multiplayer

• Sign-in, with the retired version, maintenance, and connection checks bypassed.
• Parties, Steam Invite to Game and Join Game, and peer-to-peer play over Steam.
• Voice chat and party text chat through Steam, using the game's existing voice controls.
• Free-for-all, with its queue built from the levels on your machine.

Progression

• Campaign grades, daily challenges, progression, and cosmetics, saved locally.
• A local replacement for the retired news feed on the main menu.

Creation Mode and community maps

• Creation Mode for building, editing, saving, and playtesting levels.
• Community map browsing and downloads in the in-game Discover terminal.
• In-game publishing for any Steam-authenticated creator, with attribution, reporting, and owner controls.
• Direct .ss2level export and import for sharing maps without the community service.
• The legacy maps preserved in the supported build's own local archive.

Install

Before you start

You need Windows x64, a Steam account that owns Surgeon Simulator 2, and Steam running while you play. Setup installs build 1.3.7.3054 into a folder of its own and leaves your normal Steam installation untouched.

Option 1: Setup (recommended)

1. Download SS2Revive-Setup-<version>.exe from the latest release, then run it.
2. Choose an installation folder and enter the Steam login name of an account that owns the game.
3. Complete the password and Steam Guard prompts in DepotDownloader's own window.
4. Start the game with the Launch Surgeon Simulator 2 - 1.3.7.cmd launcher Setup creates in that folder.

Setup installs the supported game build, x64 BepInEx, and the latest SS2 Revive release. DepotDownloader handles Steam credentials in its own window; SS2 Revive Setup never reads or stores them.

The setup executable is currently unsigned, so Windows may show a SmartScreen warning.

Option 2: Manual install

Use this route if build 1.3.7.3054 is already installed, or if Setup could not fetch the mod release.

1. Install BepInEx 5.4.23.2 x64 into the folder containing Surgeon Simulator 2.exe.
2. Launch the game once, then quit, so BepInEx creates its directories.
3. Download the mod ZIP from the latest release.
4. Extract the ZIP contents into Surgeon Simulator 2\BepInEx\plugins\SS2Revive\.
5. Confirm that SS2Revive.dll, SS2Revive_Data.dll, and the newsfeed folder sit together in that directory.

The x86 BepInEx build installs without reporting an error, but it will never load this 64-bit game.

Verify the install

Launch the game, then open Surgeon Simulator 2\BepInEx\LogOutput.log and look for a line like:

[Info   :SS2 Revive] SS2 Revive 1.2.1 starting.

If no such line appears, the mod did not load. See Troubleshooting.

Play multiplayer

Keep Steam running, then create or join a party through the normal in-game menus. Invite people from your Steam Friends list: right-click a friend and choose Invite to Game, or have them choose Join Game on your profile.

Gameplay traffic travels peer-to-peer through Steam instead of the retired Bossa relay services. Voice chat and party text chat travel through Steam instead of the retired Vivox service.

The Off, Always On, and Push to Talk modes, the push-to-talk binding, volume sliders, speaking indicators, and per-player mute controls all remain in the normal game UI. Steam and Windows choose the active microphone.

Community maps

Browse and download maps

Open the in-game terminal and browse Discover. Published community maps load from the public community server hosted by the maintainer and are marked ONLINE with a community icon. Browsing and downloading public maps needs no Steam website login.

Opening a community map downloads it first. Bundles and thumbnails are size-bounded, checksum-verified, cached locally, and installed only after validation. If the community service is unavailable, local maps keep working and the last valid catalogue stays available.

Publish and manage your maps

Every Steam-authenticated player can publish. Steam login only proves that the browser account matches the account running the game; it needs no maintainer approval and no upload allowlist.

1. Save a level you created in Creation Mode.
2. Open its details and choose PUBLISH.
3. Wait for local packaging and the checksum preflight to finish.
4. Complete Steam authentication in the system browser when prompted.
5. Return to the game while the bundle is quarantined, validated, and published.

The game never collects your Steam password. Republishing a map you own updates its existing community entry instead of creating a duplicate map identity. The service currently allows up to 10 upload reservations per UTC day and 25 community map identities per account.

Choose YOUR MAPS in Discover to see what you have published. ONLINE OPTIONS unpublishes a map or removes it from the public catalogue without deleting your editable local copy; publishing that map again restores its existing community entry. You can also report another creator's map for maintainer review.

Use LOG IN or LOG OUT in Creation Mode to manage the linked community session. Steam persona names appear in the details for published maps.

Share a map as a file

Direct file sharing works without the community service.

1. Open one of your local maps and choose EXPORT.

2. Find the generated .ss2level bundle in:

   %LOCALAPPDATA%\Bossa Studios\Surgeon Simulator 2\SS2Revive\export
   

3. Send the bundle and its copied 22-character share code to the recipient.

4. The recipient drops the bundle into the adjacent import folder and opens Creation Mode.

Accepted files move to import\imported; rejected files move to import\rejected, with the reason written to the game log. A newer revision updates the same imported map in place, and older or conflicting data can never silently overwrite it.

Play the bundled legacy maps

Choose LEGACY MAPS in Discover to browse levels preserved in the game's own StreamingAssets\LegacyLevels archive. These maps stay local and are never uploaded to the community service.

A legacy-format file is accepted only when it matches the archive shipped with the supported game installation. Arbitrary external maps in those older formats stay blocked.

These levels are preserved exactly as they shipped. Some are prototypes or abandoned tests and may contain bugs, unfinished objectives, placeholder objects, unusual geometry, loading failures, or a black screen. SS2 Revive can expose and safely read the files already in your game installation, but it cannot repair their original content.

Where your files live

The default SS2 Revive data directory is:

%LOCALAPPDATA%\Bossa Studios\Surgeon Simulator 2\SS2Revive

It contains:

• progress.json and progress.json.bak for progression
• levels\ for locally authored and installed levels
• export\ and import\ for direct map sharing
• cached community catalogue objects and protected authentication-session data

Progress is written atomically, and the previous version is kept as progress.json.bak. These files live outside the game and BepInEx directories, so verifying the game or reinstalling the mod does not remove them.

Configuration

The configuration file appears after the first run:

Surgeon Simulator 2\BepInEx\config\dev.ss2revive.core.cfg

The defaults give the intended restored experience, so you do not need to change anything. Every setting carries its own explanation in the file. The settings most worth knowing:

Local data and Creation Mode

Setting	Default	Purpose
Security.HardenLevelReader	true	Bounds level allocations and restricts untrusted old formats. Leave enabled.
Backend.Mode	Local	Answers retired progression and inventory calls inside the mod. Off is diagnostic only.
Backend.GrantAllCosmetics	true	Reports catalogued cosmetics as owned. Disable it to earn them through progression instead.
Backend.SaveDirectory	(empty)	Overrides the default SS2 Revive data directory. Do not point it inside the game or BepInEx folder.
Progression.SetLevelTo50OnNextLaunch	false	One-shot restore that raises the signed-in local account to level 50 on the next launch, never lowers existing progress, then resets itself to false. Requires Backend.Mode = Local.
CreationMode.Enabled	true	Enables local Creation Mode saves.
CreationMode.LevelSharing	true	Enables direct export/import and the online publishing controls.
CommunityMaps.ApiCatalogUrl	(preset)	Points at the public community server hosted by the maintainer. Leave the default alone, or clear it for a fully local library.

Multiplayer, news feed, and diagnostics

Setting	Default	Purpose
Party.SteamP2PTransport	true	Carries multiplayer traffic through Steam P2P.
Party.ShareLevelOverSteam	true	Publishes your season level through Steam so party members see the real number.
VoiceChat.SteamReplacement	true	Restores voice and party text chat through Steam, keeping the game's own voice settings and controls.
FreeForAll.Enabled	true	Builds the Free-for-all queue from available levels.
FreeForAll.IncludeGameLevels	true	Falls back to bundled game levels when no suitable custom maps are installed.
NewsFeed.Enabled	true	Uses the local replacement news feed.
NewsFeed.Url	(empty)	Serves the feed from an https:// URL instead of the local newsfeed folder.
Diagnostics.ProbeKey	F9	Writes a diagnostic state dump to the BepInEx log.
Diagnostics.Verbose	true	Includes live session and patient state in that dump. Leave it on for bug reports.

Edit the news feed

Edit BepInEx\plugins\SS2Revive\newsfeed\NewsFeed.json, then restart the game.

• Each tile defines a title, subtitle, image filename, and optional ClickUrl.
• Images belong in newsfeed\images\ as 512×289 PNG files.
• The game copies its installed artwork into that folder on first run. This repository does not distribute those assets.
• If you build from source, edit assets\newsfeed\NewsFeed.json instead.

Troubleshooting

Common problems

Symptom	Likely cause	Fix
No [Info :SS2 Revive] lines in LogOutput.log	x86 BepInEx, or the plugin is in the wrong folder	Install BepInEx 5.4.23.2 x64 and put both DLLs in BepInEx\plugins\SS2Revive
BepInEx loads, but nothing is restored	The installation is game version 1.5.x	Only build 1.3.7.3054 is supported
The mod loads, then fails around levels or saves	Only one of the two DLLs is present	SS2Revive.dll and SS2Revive_Data.dll must sit beside each other
Stuck on "requires an active internet connection"	Bypass.ConnectionCheck was turned off	Set it back to true. On 1.3.7 the game never reaches the rest of the plugin without it
Creation Mode hangs on a black screen	CreationMode.Enabled is false	Set it to true, so levels save locally instead of to the retired UGC service
Free-for-all drops you back to the lobby	The queue is empty	Enable FreeForAll.Enabled and FreeForAll.IncludeGameLevels, or install some maps
Discover shows no ONLINE maps	CommunityMaps.ApiCatalogUrl is empty, or the service is unreachable	Restore the default URL. If the service is down, local maps and the cached catalogue keep working
A legacy map opens to a black screen	The archived level is an unfinished prototype	Expected. Legacy content is preserved as shipped and the mod cannot repair it

Report a bug

1. Reproduce the problem once on the latest SS2 Revive build.
2. Press F9 for party, progression, cosmetic, or level-state problems.
3. Attach Surgeon Simulator 2\BepInEx\LogOutput.log to a GitHub issue.

The log contains your SteamID64, on the line reading Local backend is serving STEAM-.... It identifies a Steam profile but cannot be used to sign in as you; redact it if you prefer.

Report a security issue

Report authentication, upload, or backend security vulnerabilities privately to contact@macery12.xyz instead of opening a public issue.

Uninstall

• To remove only the mod, delete BepInEx\plugins\SS2Revive\.
• To remove BepInEx too, also delete winhttp.dll, doorstop_config.ini, .doorstop_version, and the BepInEx directory.

SS2 Revive does not replace your normal Steam installation. Its local saves stay in the application-data directory unless you delete them separately.

Build from source

• BUILDING.md covers building the mod, running the data tests, and packaging a release.
• backend/README.md covers the community service workspace, its local setup, and its security boundary.

Contributing

Bug reports, compatibility findings, documentation corrections, and focused code changes are welcome.

• Open an issue before starting a large behavioral or architectural change.
• Keep original game assemblies, decompiled source, credentials, and Bossa-owned assets out of commits.
• Read BUILDING.md before submitting a pull request.
• Include reproduction steps and a log for runtime bugs.

License and disclaimer

SS2 Revive source code is available under the MIT License.

This is an unofficial, non-commercial fan modification. It is not affiliated with, endorsed by, sponsored by, or connected to Bossa Studios, Curve Games, or anyone else involved in Surgeon Simulator 2. All related trademarks, copyrighted game assets, and game code belong to their respective owners.

The repository contains no original game code and no game assets. The mod reads data from a copy of the game you own, and exists to keep purchased functionality usable after the original online services were shut down.