NyanBot

A Bonelab nextbot mod (MelonLoader + BoneLib). A flat 2D Nyan Cat sprite with looping music chases players, launches them into the air, and kills them on contact. Works single-player, and in Fusion lobbies where the host runs the cat and everyone else sees and hears it.

Status: written without access to the game, so it has not been compiled or tested in-game. Some game/BoneLib/Fusion names may need small fixes. See Troubleshooting.

Features

• 2D billboard sprite that always faces the player
• Looping 3D audio, so you hear it coming
• Chases the nearest player; collides with walls and floors, has gravity, and jumps over obstacles
• Never jumps when close, and ignores player colliders, so it can't land on (or get stuck on) your head
• Touching it launches you, then kills you
• BoneMenu buttons to spawn and despawn it
• Fusion multiplayer sync (host-authoritative)

Requirements

• Bonelab (PC) with MelonLoader installed
• BoneLib in Mods/
• LabFusion in Mods/ (only needed for multiplayer)
• To build: .NET 6 SDK
• Launch the game once with MelonLoader before building, so it generates MelonLoader/Il2CppAssemblies

Install (for players)

Every player in a lobby needs the same three things, otherwise they won't see or hear the cat and can't be killed by it:

1. NyanBot.dll in the game's Mods/ folder
2. nyan.png (transparent sprite) in UserData/NyanBot/
3. nyan.wav (or nyan.mp3) in UserData/NyanBot/

Build

1. Set your game folder. The default is C:\Program Files (x86)\Steam\steamapps\common\BONELAB. To override:

   dotnet build -c Release -p:GamePath="D:\path\to\BONELAB"
   

   or create NyanBot.csproj.user:

   <Project><PropertyGroup><GamePath>D:\path\to\BONELAB</GamePath></PropertyGroup></Project>
   

2. Close the game first. If it's running, the old DLL is locked and can't be overwritten.
3. After a successful build, the project copies NyanBot.dll into Mods/ and the contents of UserData/NyanBot/ into the game's UserData/NyanBot/.

Use

Open the BoneMenu and go to NyanBot:

Desktop test keys: F9 spawn, F10 despawn.

On startup the MelonLoader console should show NyanBot 0.3.0 loaded and NyanBot audio loaded: 17.8s. If you don't see the version number, an old DLL is still in Mods/.

Multiplayer (Fusion)

• Only the lobby host can spawn and despawn the cat.
• The host runs the real bot and chases the nearest player in the lobby.
• The host streams the cat's position about 20 times a second. Other players get a puppet with the same sprite and looping audio. Late joiners get one automatically.
• Each player's own game decides whether the cat is touching them, and launches and kills only that player.
• Each player can opt out with the Nyan Cat can kill me toggle.
• Without Fusion, or outside a lobby, everything works single-player.

Tuning

Adjust at the top of the NyanBot class in NyanBot.cs:

Hit behavior is in NyanHit: LaunchForce (40), KillDelay (0.4 s), TouchPadding (0.5 m). The 3 m no-jump radius is nearPlayer in NyanBot.Update, and the 2 m touch radius is in NyanHit.Touching.

Troubleshooting

Build errors about missing types (RigManager, Player_Health, ...): an assembly isn't referenced. Check what's in MelonLoader/Il2CppAssemblies and add it to the .csproj. Newer Bonelab builds keep these in Il2CppSLZ.* assemblies, which the project already picks up.

MelonUtils.UserDataDirectory obsolete: already fixed (uses MelonEnvironment.UserDataDirectory).

BoneMenu errors: the code targets the BoneLib 3.x menu API (Page.Root.CreatePage). For BoneLib 2.x, use the alternative calls in the comment inside SetupMenu().

No audio: check the console for NyanBot audio loaded or an error naming the expected file. The mod loads nyan.wav itself (16-bit PCM) and falls back to nyan.mp3.

Sprite is pink or invisible: the Sprites/Default shader may not be in the game build. Swap in one that is.

It doesn't kill you: the console logs which health member was used (NyanBot killed via ...). If none matched, it prints the available method names, so the right one can be added to KillPlayer.

Doesn't show up for other players: every player needs the mod, the same files, and Fusion. Only the host can spawn it. Check each player's console for NyanBot: Fusion detected.

Spots to verify if something breaks: lines marked VERIFY in NyanBot.cs (Player.Head, Player.PhysicsRig, Player.RigManager, the sprite shader). These come from BoneLib and the game and can change between versions.

Files

NyanBot.csproj          project file (set GamePath)
NyanBot.cs              mod: spawning, chase/physics, audio, hit logic, BoneMenu
FusionBridge.cs         all Fusion-specific code (message + sync)
UserData/NyanBot/       nyan.png, nyan.wav, nyan.mp3

Assets and credits

Nyan Cat's artwork and music belong to their respective creators. The sprite and audio here are files supplied by the mod's author for personal use. Don't redistribute them, for example by uploading to a public mod site, without the rights to do so. Swap in your own files at any time by replacing the files in UserData/NyanBot/.

Multiplayer uses LabFusion's module/message API.