ModinMobileSTS/Sts2MobileLauncher

What it does

Slay the Spire 2 is a PC game built on Godot/Mono. This project is an unofficial Android shell that imports the user's own PC game files and boots them on a phone or tablet. It does not ship any game assets; the base game must come from an archive the user supplies or from a Steam download performed inside the app after login (repository description).

The app is split into three parts: the Android launcher shell (importing, Steam login and download, Workshop browsing, save snapshots/sync, mod file management), an Android compatibility pack loaded through a Harmony-based hook at game startup (input adaptation, path redirection, shader replacement, mod loader bridging), and the user-provided base game (project structure). Extras include a full software keyboard, a floating touch-mouse button, multiplayer reaction-button restoration support, and an optional log-analysis page that talks to an OpenAI-compatible endpoint.

It targets players who already own the PC game and want to play it on Android, often with mods.

Getting started

There is no prebuilt binary described in the README; the documented path is building the importer APK yourself. A complete first run looks like this:

1. Install Linux, macOS, or WSL with JDK 17+, Android SDK (API 35) and NDK, the .NET SDK, and Python 3.
2. Clone with the compatibility-pack submodule: git clone --recursive https://github.com/ModinMobileSTS/Sts2MobileLauncher.git, then cd Sts2MobileLauncher.
3. Copy the environment templates (cp .env.example .env, cp local.properties.example local.properties) and fill in JAVA_HOME, ANDROID_HOME, DOTNET_BIN, and the original PC DLL reference paths.
4. Sync runtime artifacts with tools/android/sync-runtime-from-references.sh. The Android FMOD engine and Godot bridge must match the PC game's 2.03.06 release.
5. Stage the compatibility packs with tools/android/stage-bundled-compat-artifacts.sh.
6. Build the importer APK with tools/package/build_importer_apk.sh; the output is dist/sts2-re-importer.apk.
7. Install the APK, log into a Steam account that owns the game (or import a local SlayTheSpire2.zip or another supported archive), and launch. If no matching compatibility pack exists for the payload, the launcher offers a recommendation sheet.

Full environment details are in the build and packaging guide; connected-device automation is covered by the ADB debugging harness.

Constraints and risks

• Device and runtime: Android 7.0+ is the stated platform, with Godot 4.5 Mono underneath. The release build keeps debuggable=true for log capture, so any computer with ADB access to the phone can extract app data, including encrypted Steam credentials (security notes).
• Account data: Steam passwords and Guard codes stay in memory; a refresh token is stored encrypted locally. The README recommends using only an APK you compiled yourself or obtained from a highly trusted channel.
• Mods are arbitrary code: C# mods can bypass the sandbox and read local files, including stored Steam tokens. Log out of Steam in the app before installing mods from untrusted sources.
• Partial coverage: Player counts above four are experimental; general vanilla screens may still assume four players. Portrait mode requires a separate portrait UI mod; the launcher does not provide one. Downloading an older or custom Steam manifest does not guarantee Android compatibility.
• License: MIT for the launcher itself; bundled third-party components (e.g., Spine runtimes, Godot) keep their own licenses (third-party licenses).

HotRepo's take

The project appeared in the Java daily ranking on 2026-11-14 at 10th place with 573 stars, adding 13 stars that day on a 22-fork base. That is a single recorded snapshot, so it supports only that day's position, not a longer trend. The README's level of detail — versioned compatibility pack targets, save-path separation between modded and normal saves, and documented build scripts — is consistent with a real community project around a specific game, and the MIT-licensed launcher plus self-contained documentation make it a plausible pick for players who own the PC title and are willing to build the APK themselves.