Cinematic vector animation, streamed from microSD.
A 48 MHz RISC-V, 20 KB of RAM, and a 128 × 128 window into Another World.
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Explore the project
A late-night experiment. A flash of light. Cold water beneath an alien sky.
Other Realm brings the polygon animation and scripted adventure of Éric Chahi's Another World to the CHGame handheld. The engine draws the original vector scenes as they play, reading scripts, shapes, and palettes from the SD card. A small, purpose-built interface adds autosaves, readable menus, and a little magic.
Recorded from the real C++ engine in the simulator. Selected shots retain their engine timing; enlarged 3× for this page.
- Vector scenes on demand. Polygon hierarchies and cooperative bytecode tasks stream from SD through a small sector cache.
- Pick up where you left off. Nineteen original checkpoint destinations save automatically. No passwords to remember.
- Made for 128 × 128. Patched text screens, native bitmap menu fonts, full-screen title art, and a gently pulsing start prompt.
- A quiet bit of atmosphere. Menus fade over the darkened scene, with wandering sparkles, selection dust, and a soft confirmation burst.
- A reward for finishing. Complete the game to unlock the raised-hand greeting as your title background.
- Your files, your cartridge. The patcher validates your original resources, adapts them, renders the title scenes, and packages a personal
.chgame. - An original game included. Signal Grove is a small, freely distributable vector adventure for trying the engine or learning to author scenes.
| Button | In the game | In menus |
|---|---|---|
| D-pad | Move; Up jumps or swims upward | Up / Down selects |
| A | Action, run, shoot | Confirm |
| B | Jump shortcut | Back; return from the main menu to the title |
| Start | Tap to pause; hold 3 seconds to return to the CHGame launcher | Resume / back; hold to exit |
| Select | Open the pause menu | Back |
At the very beginning, hold Up + A to swim out of the pool. Once Lester has climbed onto the bank, move away from the water. Hold A with a direction to run. Later, the action button also controls the gun; how long you hold it matters.
Every boot begins at the title. A new game starts with the intro; press Start during it for Skip Intro. Resume keeps your exact current position in memory. Retry Save and Continue restart at the latest earned checkpoint. Starting a new game asks before replacing an existing checkpoint. Sound can be toggled in the menu.
Support the original creators: Another World — 20th Anniversary Edition on Steam.
Current release: Amiga profile, Steam import pending. The validated patcher accepts the English Amiga ADF pair used during development. The Steam edition uses different resources and has not yet been validated. Buying Steam alone does not currently provide the ADF input this release needs. You can try the included original Signal Grove game without supplying any commercial data.
To locate a Steam installation, use Library → Another World → Manage → Browse
local files. The anniversary edition keeps its resources under game/DAT,
game/BGZ, and game/TXT. Keep that folder intact for future Steam support;
renaming those files will not turn them into the supported Amiga edition.
For the current profile, place both of your original Amiga .adf disks in one
folder. The patcher checks the executable and scripts before applying adaptations;
an unsupported revision stops with an error instead of producing a broken game.
Download Otherrealm-Patcher-Windows.zip from Releases. Extract the entire folder, open Otherrealm-Patcher.exe, choose your source folder and a new output folder, then click Build my cartridge.
No Python, Node, compiler, or online account is needed to run the Windows patcher. It leaves your source files unchanged and writes:
| Output | What it is for |
|---|---|
Otherrealm.chgame |
Personal cartridge with firmware, cover, metadata, and your adapted game data |
sdcard/ |
Two ready-to-copy files for the SD card |
Otherrealm.bin |
Firmware for direct USB upload |
cover.png |
Native 128 × 128 cartridge art |
patch-report.json, verification.json |
Applied changes, input hashes, and package validation |
START-HERE.txt |
A short installation and controls guide |
Keep the generated cartridge and game pack private. They contain your original game data. The public downloads contain the engine, patcher, and original demo.
With the CHGame desktop tools installed and your FAT16/FAT32 card mounted, import the cartridge into the card's game collection:
chgame cart deploy .\Otherrealm-personal\Otherrealm.chgame --card E:\ --port COM8 --no-flashUse your own drive letter and port. Safely eject the card, put it in CHGame, and select OTHER REALM. The bootloader installs the game from the card.
Using the Arduino board-package uploader: first copy the contents of the
generated sdcard/ folder to the card root and safely eject it. From the extracted
Windows patcher folder, run:
.\Upload-Cartridge.ps1 -Cartridge C:\Games\Otherrealm-personal\Otherrealm.chgame -Port COM8The helper validates and extracts the .chgame, then calls the installed
chgame-upload tool from the CHGame board package. That uploader accepts firmware
images rather than .chgame archives directly. The SD data is needed with either
installation method.
See the complete installation guide for tool setup and troubleshooting. Prefer compiling the engine and copying files yourself? Follow the developer method with Arduino CLI.
The small amount of RAM limits what is visible at once, not how much adventure can live on the card. The engine keeps four drawing pages in memory and fetches the scripts and shapes needed for the current scene. A scene can replace its resources without recompiling the firmware.
| Resource | Current CHGame Rev0 build |
|---|---|
| CPU | CH32X035, 48 MHz RISC-V |
| Application image | 33,808 bytes |
| Static RAM | 17,980 bytes |
| Reserved stack / measured peak | 2,048 bytes / 1,040 bytes in the profiled run |
| Drawing pages | Four 104 × 65 pages, 16 colors; 13,520 bytes total |
| Display | 128 × 80 gameplay preserving 8:5; 128 × 128 titles and interface |
| SD cache | Three shared 512-byte sectors |
| Adapted development game pack | 1,456,640 bytes, including both title backgrounds |
The integer renderer, interpreter, and session code also compile to WebAssembly. The browser preview runs the same C++ engine and reads a selected game pack locally. Resource conversion and decompression happen on the computer, before play. No second full-screen framebuffer is needed on the handheld.
This is a vector engine with bitmap compatibility for the original game's few bitmap scenes. It has no desktop SDL dependency, sampled-audio mixer, or visual scene editor. Each script/shape segment has a 64 KiB address space; larger adventures use more scenes. Card capacity does not remove those per-scene limits.
Explore the engine overview, pack format, text patches, checkpoints, hardware measurements, and title/menu design.
The complete intro and opening gameplay have run on the handheld. Automated tests cover startup replays of all seven gameplay parts, nineteen checkpoint destinations, save persistence, rendering, and the original demo. This is not a claim of a complete end-to-end playthrough. See test evidence.
Sound uses lightweight piezo cues; the original sampled soundtrack and effects are not mixed. The flash journal retains one installed game's save, so another game's first save can replace it. Browser saves are separate from device saves. Fractional scaling of the gameplay canvas can make some in-game lettering uneven; menu fonts are rendered at native screen resolution.
Native 128 × 128 cover, composed from an original game scene and the Other Realm wordmark.
The world we are visiting
- Éric Chahi — creator of Another World, its design, programming, and artwork.
- Jean-François Freitas — the original music and sound.
- Delphine Software — the original publisher.
- Éric Chahi and DotEmu, with The Digital Lounge — the Steam 20th Anniversary edition.
The work that made this adaptation possible
- Gregory Montoir — RawGL and the interpreter lineage that documents the game's behavior and formats.
- Fabien Sanglard — Another World Bytecode Interpreter, whose annotations informed this implementation. The compatibility font/string tables retain their upstream license.
- G. Megidish — Another World Hebrew patcher, inspiration for adapting resource scripts. No code or assets from that patcher are included.
- Kevin Bates / bateske — CHGame, the hardware, board package, SD support, bootloader, cartridge tools, and direction of this adaptation.
- The X11 Misc Fixed font contributors — public-domain 8×13 Bold and 5×8 bitmap fonts, sourced from PixelLogoLab.
- Ethan's Critters — the README structure and presentation template.
- OpenAI Codex — implementation and testing assistance, directed and playtested by Kevin Bates.
More useful exploration: noteed/exploring and Another World source reconstruction. Exact source revisions, imported components, and notices are in THIRD_PARTY.md. Media capture provenance is in docs/MEDIA.md.
| Component | License |
|---|---|
| Portable engine and applicable source tools | GPL-2.0-or-later |
| Combined device build and release packager | GPL-3.0-or-later |
| Original Signal Grove content and Other Realm wordmark | CC0-1.0 |
| Original Another World game content | Rights remain with its respective owners; not included as playable data |
This is an independent compatibility project, not an official port or an endorsement by the original creators. Screenshots and gameplay footage depict the original game; they are not reusable GPL/CC0 game assets. Do not redistribute generated personal cartridges, extracted banks, disk images, or adapted game packs.