AM2R for Android — Autopatcher

Turns your own copy of the original AM2R 1.1 release (AM2R_11.zip) into the Standard or Dual Screen Android APK, entirely on your Android device. Nothing playable is distributed here: the game data is rebuilt from your files, and the result is verified byte-for-byte against this build's checksum before installation.

The port is based on AM2R Community Updates 1.5.5 and runs natively on ARM64 Android. The autopatcher creates the game APK. Once installed, the game launches independently and does not require the autopatcher to remain installed.

1.5.5.14 — Touch-control adjustment and Retroid Dual Screen Add-on support.

Standard adds a Diagonal Aim Size slider under Control Options. Increase it for larger diagonal aim arrows and a smaller joystick inside the same control area. Overall scale and spacing remain independent, and touch targets follow the visible controls. The controls menu now scrolls far enough to show Done.

For Retroid Pocket Nova with the Retroid Dual Screen Add-on, choose the Retroid Pocket Duo / Duo Lite profile and enable Dual Screen Add-on in Display Options. Gameplay fills the external 16:9 panel while the map and menus stay on the handheld. The setting defaults off for ordinary Duo/Duo Lite devices; the RG DS screen-order option remains separate. Nova add-on operation is confirmed through community testing.

Fixes the error when water appears on screen in Standard and Dual Screen, with Nano enabled or disabled.

Both editions include Display Options → Nano for devices that need lighter visual effects. It reduces decorative particles, some lighting and glow effects, and background map animation while keeping normal game speed, combat and controls. Turn it off to restore full visuals. Other display and rendering efficiencies apply in both modes.

Dual Screen adds Swap Displays for the RG DS profile. First-time RG DS setup previews the screen order and starts Nano enabled. Both choices remain adjustable in Display Options; updates preserve saved preferences. RG DS has been tested on stock Android, with additional community GammaOS testing. Nano improves performance.

Includes the gallery fix from 1.5.5.12 Hotfix 1 and the earlier UI improvements.

Menus and new Android settings now share the English layout across the existing language selection, using the original community fonts. Long help text scrolls inside its fixed strip. Dual Screen HUD actions, area titles and controller hints follow the selected language; timer punctuation and the completion symbol keep their original style. The Spanish selector is labeled Español.

Nano now limits decorative bubbles from broken pipes, pauses distant crabs and keeps the darkest Industrial Complex breeding-ground rooms visible. Nearby combat stays active. Shared burrowing-enemy and reactor-escape fixes reduce unnecessary work in both modes. Mining Facility breeding grounds now use their discovered-area title and background. Compact lower-screen layouts keep the two Metroid counters together and place the energy bars beside health.

Both editions retain improved frame pacing, exploration and rendering efficiency while preserving the game's artwork and gameplay. Dual Screen has a redesigned lower HUD and consistent menu buttons with controller hints. Returning to the game loads textures faster, and title scrolling follows the music on slower hardware.

Standard now offers Display Options → Aspect Ratio: 4:3 / 16:9 / 3:2. The 3:2 view fits GBA-shaped displays without stretching the artwork. If changed during gameplay, it takes effect at the next room transition. Existing widescreen preferences are preserved when updating.

Standard offers draggable Touch Control Scale and Control Spacing sliders under Control Options. The visible controls and touch targets move together; camera-cutout clearances remain automatic. Display Options includes Orientation: Landscape / Portrait / Automatic. Landscape is the default. For a Surface Duo, select the desired orientation and use Android's unspanned app window on the intended panel. A spanned upper/lower Surface Duo layout is not implemented.

The 1.5.5.11 Hotfix 1 Hold-mode Weapon Select button remains above Arm when both missile types are available. Hold Arm and tap Weapon Select to switch missile types. Toggle mode and physical controller controls keep their existing behavior.

Discovered Genetics Laboratory entrance rooms retain their area title, including the Hydro Station pipe and visits after a save transfer. GF Research Site has its own discovered-area title and background. The Tower's exterior title appears after its area scan, and the Waterfalls rooms now show their title.

Earlier features remain included: improved Standard touch timing, shared-folder save synchronization, Mining Facility artwork, the controller splash, refreshed icons and installation failure reports. Normal gameplay and controller mappings remain unchanged.

What you need

• Your copy of the original AM2R 1.1 Windows release (AM2R_11.zip, the 2016 freeware release). A Community Updates or modded copy will not work — the autopatcher checks the exact original data.win.
• An ARM64 Android device running Android 10 or newer for the autopatcher.
• For Dual Screen, a supported Android handheld with two displays and built-in controls, or Retroid Pocket Nova with the Retroid Dual Screen Add-on. Included profiles are AYN Thor, RG DS, Retroid Pocket Duo / Duo Lite and AYANEO Pocket DS.
  • AYN Thor: tested and working.
  • AYANEO Pocket DS: tested and working, confirmed through community feedback.
  • Retroid Pocket Duo / Duo Lite: both tested and working through community feedback. Duo Lite testing also confirmed audio remains working after switching apps.
  • RG DS: tested on stock Android, with additional community GammaOS testing. Swap Displays corrects reversed screen order; Nano helps performance. Demanding scenes can still slow down.
  • Retroid Pocket Nova + Retroid Dual Screen Add-on: tested and working through community feedback. Use the Retroid profile with Dual Screen Add-on enabled. RG DS Plus is not included.

How to use

1. Put your AM2R_11.zip somewhere on the device that Android's file picker can reach, such as Downloads or an SD card.
2. Install the AM2R-Autopatcher-1.5.5.14.apk from the release. Allow installation from your browser or file manager when Android asks.
3. Open AM2R Patcher and choose Standard for one screen, or Dual Screen for a handheld or supported add-on with one of the included profiles.
4. Select your original AM2R_11.zip and wait for patching to finish. The verified game APK is saved in Downloads. Your original ZIP stays unchanged.
5. Tap Install Standard or Install Dual Screen to open Android's installer. Allow AM2R Patcher to install the generated APK if Android asks.
6. If installation fails, the patcher saves a diagnostic report in Downloads. Use its Share action or attach the file to a GitHub issue. It is never uploaded automatically. The generated APK remains in Downloads.
7. Open the installed game directly. Dual Screen asks you to choose your hardware on first boot; the same choice remains available in Display Options. RG DS then asks you to check the screen order. Select Swap Displays until gameplay is on the intended panel, then Keep This Order.

Updates install over the existing edition — saves are kept. Back up your saves before updating. Uninstalling the game deletes its app-private saves. Standard and Dual Screen install as separate applications and have separate save storage.

Install the new Autopatcher and repatch your original ZIP to update either game. Updating the Autopatcher alone does not replace an already installed game.

Standard and Dual Screen

• Standard keeps gameplay and menus on one screen, with touch and controller support. Display scaling is automatic.
• Dual Screen puts gameplay above and a live map below. Display Options → HUD Screen Position keeps health and ammunition below or restores the original HUD above. One consistent lower-screen style is used for the map, menus, timer and completion percentage. Moving health and ammunition above removes their unused space below. The lower HUD uses blue energy bars, yellow health digits, grouped ammunition and Metroid counters. Unacquired Super Missile and Power Bomb panels stay hidden until acquired. Long area names fit within their title panel. A single bottom toolbar shows map controls during play and Marker / Menu / Unpause on the paused map. Touch can pan and zoom the map while gameplay continues. Fit Map frames the revealed map; Follow returns to the last manual zoom and tracks the player's map cell. Pausing freezes and dims the upper screen while the lower map, inventory, logs and settings remain usable. Area backgrounds change with the current subarea and its progress after its original environment scan has revealed it. The map stays visible during normal room transitions; reactor flashes affect both screens. The reactor temperature warning stays on the upper screen with either HUD choice. With Nano disabled, the lower display receives every game draw. Nano reuses an unchanged map image between updates; player, HUD and input changes refresh it.

In Dual Screen, the gameplay aspect-ratio setting affects only the upper screen. RG DS locks that screen to 4:3. Retroid Pocket Duo and Duo Lite share a profile. Dual Screen uses the handheld's controller for Samus and the lower touch interface for the map and menus; it does not use the Standard edition's on-screen gameplay controls.

Fresh profiles begin with completion-gated modes and extras locked. Earned progress and restored unlock records are kept. The existing secret unlock sequence remains available.

Both games retain their released package IDs and signing certificate. Android labels are AM2R: Return of Samus and AM2R: Return of Samus DS. Both game packages use version code 1005014; Android version names are 1.5.5.14 and 1.5.5.14 DS. The Autopatcher version is 1.5.5.14, version code 18. Private preview applications remain separate from the release editions.

Game-category declarations are included for frontends. Cocoon documents manual artwork and description editing, but automatic import of our metadata is not confirmed. The source includes a central metadata definition and export helpers. Both final game APKs pass static 16 KB ZIP and ELF alignment checks. Installation and gameplay on 16 KB-page Android devices still need physical validation.

Saves, backup and synchronization

Both editions use Options → Data → Backup / Restore. Backups can transfer progress between Standard, Dual Screen and PC Community Updates 1.5.5. Choose the incoming save and destination slot before confirming a restore. Settings and controller bindings stay specific to each installation.

Options → Data → Sync Folder can connect either edition to a folder copied by a service such as Syncthing. This is optional and disabled until you choose a folder. The game checks for incoming progress before file selection and exports after saving; it does not replace progress during active gameplay. Conflicting changes are held for review, and recovery copies are retained. There is no built-in network service: configure your preferred file-sync app separately. Read SAVE-SYNC.txt for setup and recovery details. Real Syncthing transfers passed between two isolated Android emulators and a Linux PC, including conflict review and loading transferred progress. Physical-device sync, Windows/macOS and other services remain unverified. Unmodified desktop builds do not read the sync transport directly; use manual Backup / Restore for those transfers.

For Android to PC, copy the files inside the timestamped backup folder into the PC save directory while the game is closed. Preserve a copy of existing PC saves. Windows uses %LOCALAPPDATA%\AM2R; the tested Linux build uses ~/.config/AM2R. For PC to Android, select a folder containing the PC saves in Restore, then choose the incoming and destination slots. Records and unlocks are a separate choice. The original 1.1 ZIP is the patching input; compatibility with 1.1 or modded save files is not implied.

How it works

The autopatcher bundles separate patch data for each edition: wrapper.bin (the port's engine, code and community content with the original-game byte ranges cut out), droid.xdelta (a binary delta that reconstructs the game data from your 1.1 copy), and assembly.json (the splice plan, with a checksum for every segment).

It verifies your data.win, rebuilds the game data with xdelta3, splices everything back together in order, and accepts the result only if the final hash matches the expected build. Because reconstruction is byte-exact, the signature carries over: every successfully patched APK for an edition is identical to that edition's signed build. A complete playable game APK is not included in this package.

For a native game rebuild, apply both prepare_game_metadata.py and prepare_runtime_performance.py --runtime-copy /path/to/isolated/runtime to the pinned runtime copy. Build each edition using Android ARM64 YYC. The second helper preserves the shared method cache; skipping it loses that optimization. Keep the complete local projects and media separately from source exports.

Release files

• AM2R-Autopatcher-1.5.5.14.apk
• AM2R-Autopatcher-1.5.5.14-source.zip
• AM2R-1.5.5.14-standard-source.zip
• AM2R-1.5.5.14-dual-source.zip
• SHA256SUMS

Run sha256sum -c SHA256SUMS from the download folder to verify all four files. Source archives retain code, resource definitions and required license notices; they omit artwork, audio, fonts, compiled games, generated patch payloads and signing material. Restore the game project assets with the matching separate AM2R Project Assets developer tool and your original 1.1 ZIP. GameMaker and its documented runtime must be installed separately. Complete playable game APKs are not provided.

Known limitations

Known issue — Dual Screen launcher compatibility

Some Cocoon setups may reduce performance because the launcher continues running behind the lower display, particularly at low clock settings. This release keeps the display behavior that restored audio on the Retroid Pocket Duo Lite.

The lower display can still take a moment to resume, especially at low clocks. Performance varies with the device, power preset and other running applications. Testing and community feedback do not guarantee identical performance on every handheld or in every room. Both game APKs pass static 16 KB alignment checks; installation and gameplay on 16 KB-page devices still need physical validation. Surface Duo orientation is supported through an unspanned Android app window; a foldable upper/lower split is not implemented.