Multibonk — MegaBonk Multiplayer

Unofficial community co-op mod for MegaBonk. Thunderstore package 0.2.7; DLL v0.2.5 / network protocol 111. All players must use the exact same release DLL and game version.

Package 0.2.7 — branding and documentation only

This package updates the Multibonk icon, website links, and documentation. The included Mods/Multibonk.dll is byte-for-byte identical to the published v0.2.5 DLL. Its internal version remains 0.2.5 and its network protocol remains 111. This package adds no gameplay or networking changes, including no Steam-invite functionality. Players using the original v0.2.5 release DLL already have the same executable mod code.

• Multibonk website
• On-site feedback and bug reports
• Source and public mod releases

Requirements

• Owned Windows x64 MegaBonk installation. Tested game build: 1.0.69.
• MelonLoader 0.7.3 x64 / IL2CPP, installed separately.
• The loader's .NET 6 Desktop Runtime x64 requirement; see the official loader instructions.

This is a MelonLoader mod, not a BepInEx plugin. The package does not install MelonLoader. Manual installation is described below; one-click manager installation has not been verified for this release.

Manual installation

1. Close MegaBonk and back up your saves and any existing Mods/Multibonk.dll.
2. Steam: right-click MegaBonk → Manage → Browse local files.
3. Install MelonLoader0.7.3 for Megabonk.exe. Launch once, let initialization finish, then close the game.
4. Extract this package and copy Mods/Multibonk.dll into the game's Mods folder. Replace the previous DLL; keep only one copy.
5. In Steam Properties → General → Launch Options, enter --multibonk-port 35565.
6. Start the game. F5 opens the connection panel.

Existing users only need to replace the DLL while the game is closed. No launcher scripts, bot tools, game files or loader binaries are required from this package.

Host and join

1. Everyone selects a character.
2. One player chooses F5 → Host and allows TCP35565 through Windows Firewall.
3. Friends choose F5 → Join, entering HOST_ADDRESS:35565.
4. The host clicks Start Game, or presses F8, once the party appears.

Same LAN: the host runs ipconfig; friends use the host's LAN IPv4 address, for example 192.168.1.20:35565. No router port forwarding is required. Guest-network isolation can block access.

Different networks: the host forwards TCP35565 to their PC's LAN IPv4 address and allows it through the firewall. Friends use the host's public IPv4 address followed by :35565. Carrier-grade NAT/double NAT may prevent direct inbound connections. No Steam-invite/relay service is included.

The built-in default without the launch option is TCP25565. An address without a port also assumes25565; always include :35565 for this guide. Do not forward the local developer control socket.

Gameplay and current status

[PROXY] Feature scope: host-authoritative enemies/stages, shared XP/level/gold, synchronized level-up choices, shared chest/shrine reward choices, party reward pauses/waiting messages and remote character/attack visuals.

• One shared boss chest; its choice is shared with current living, loaded participants. Each player chooses personally.
• Merchant and microwave transactions remain personal.
• Downing/party wipes are handled; a separate manual revive mechanic is not implemented.

[RAN] The published DLL compiled and loaded in an actual local host/client session. [SAW] Gameplay was inspected; the owner reports the portal transition working. Full gameplay/visual coverage and other game builds are not established.

Known issues

• Remote character textures/materials can appear incorrect or bright magenta.
• Remote VFX can differ from the owner's effects; hats are not synchronized.
• Native live-particle array capture is disabled after a development crash; this release uses the prefab seed/time fallback.
• Downed players cannot activate normal portals; a living participant can do so.
• Linux/Steam Deck, other game versions and combinations with other gameplay mods are unverified.

Troubleshooting and issues

• Website feedback form: describe what happened, how to reproduce it, your game/mod versions, and whether you were Host or Client. The form offers an optional reply email. Avoid sending passwords, API keys, or private save/account information. GitHub issues remain available below.

• No F5 panel: check loader initialization, DLL placement and MelonLoader/Latest.log.

• Cannot join: host first, match DLL/game versions, include the port, and check firewall/router settings. A joining Windows PC can run Test-NetConnection HOST_ADDRESS -Port 35565.

• Preserve both host/client MelonLoader/Latest.log files before relaunching after a problem.

• Report a bug or request a feature. Include versions, host/client role, player count, reproduction steps and screenshots/logs. Remove personal information before posting logs publicly.

• GitHub releases and version history.

Uninstall

Close the game and remove Mods/Multibonk.dll, or restore its backup. MelonLoader can be removed separately using its own instructions.

Credits and license

Original mod: Guilherme Luiz (2025). Server-authoritative rewrite: AvinadavCoh (2026). Development assistance: OpenAI Codex. MelonLoader/Harmony/Il2CppInterop are supplied by the separate loader installation. Co-op Anything was used for development testing and is not bundled or required at runtime.

Branding: AI-generated fan illustration of MegaBonk's Calcium skeleton (black sunglasses) and Fox wizard (blue pointed hat/cloak and firestaff), created with OpenAI's built-in image-generation tool using publicly viewable character/gameplay references. This is unofficial fan art, not official game artwork or an endorsement. The underlying character designs and MegaBonk trademarks remain with their respective owners. Downloaded reference images are not included in this package.

MIT license: see the included LICENSE. No game files, decompiled source, loader files or bot tools are bundled.