Loading code into Unity games (BepInEx and Doorstop)

None of the Unity games here has a built-in mod loader. Code reaches them through Unity Doorstop, a proxy DLL placed beside the executable (winhttp.dll) that reads doorstop_config.ini and runs BepInEx\core\BepInEx.Preloader.dll before the game’s code. Sourced · Unity Doorstop BepInEx then loads plugin assemblies from BepInEx/plugins. Sourced · BepInEx

Game	Loader	What a loader-equipped install shows	Confidence
SkateBIRD (Mono)	BepInEx 5 (x64)	the game’s code never loads a bundle or a mods folder, so a loader has to be injected	Observed · SkateBIRD
PEAK (Mono)	BepInEx 5	winhttp.dll, doorstop_config.ini (Doorstop with the preloader as target assembly) and a BepInEx/plugins folder beside PEAK.exe	Observed · PEAK
Big Walk (IL2CPP)	BepInEx 6	winhttp.dll, doorstop_config.ini, a dotnet runtime folder and BepInEx/interop, core, cache, config folders, which are an IL2CPP loader’s layout	Observed · Big Walk

The loader files in the table are not part of the shipped game; they are what an install with the loader added looks like. Observed

BepInEx 6’s changelog in the Big Walk install lists “improved support for IL2CPP metadata v23 to 106 (Unity 6+)” and a Doorstop upgrade to 4.5.0. Observed · Big Walk

What a plugin can do in each game

A plugin on a Mono game can call AssetBundle.LoadFromFile, SceneManager.LoadScene(..., LoadSceneMode.Additive) and set the camera. It must be built against assemblies of the same Unity line (SkateBIRD’s 2019.4.20f1) for serialized compatibility. Sourced · BepInEx

PEAK’s community documents flag two fitting traps for character mods: the order of the bones and the game’s W/Character shader. Sourced · peak-more-customizations

Loading a Sledding Game plugin

Sledding Game’s install ships FishNet and has no Doorstop files; how a plugin would be loaded into this IL2CPP build is not established.

SkateBIRD

For SkateBIRD, a plugin placed in a copy of the install can load scenes, teleport the player and lock Camera.main at an exact pose and field of view with the HUD, the bird and the lens effects off. The game runs without Steam: its SteamClient.Init failure is caught. Observed · SkateBIRD

Community scene

SkateBIRD has no dedicated mod platform: its Thunderstore community page does not exist, the Nexus page showed no mods, and the Steam guides cover no modding. Ten GitHub repositories (SIGFAI/skatebird-*, updated October 2026) are AI-generated “takeover” plugins built on BepInEx 5. Sourced · GitHub search, 2026-10-18