lp-engine

LovePlus+ (Konami, 2010) on PC and Mac, in English, sharper than it ever looked on a DS.

lp-engine runs the Nintendo DS game LovePlus+ from your own copy of the game, with a complete English translation and modern rendering: up to 4× resolution, anti-aliasing, smoothed animation and upscaled textures. It isn't a general DS emulator. It's an engine built around this one game: the game's own logic runs unchanged, and the hardware around it (graphics, sound, touch screen, microphone, clock, saves) is reimplemented for your computer.

_{Captured from the engine at 4× resolution with texture filtering, smooth toon shading, anti-aliasing and enhanced textures. The two screens sit side by side, the way the game is held.}

What you get

• The whole game in English. All 29,000 lines of dialogue, plus menus, messages and the game's drawn-in UI graphics, redrawn in its own pixel font. A few spots keep their Japanese on purpose (the vocabulary quiz, name readings).
• A sharper picture. The 3D is drawn at up to 4× resolution on your GPU, with optional anti-aliasing, texture filtering, smooth toon shading and 30 fps character animation. Textures and photo backgrounds can be upscaled (FSR, with a denoised "smooth" preset). The pixel-art UI stays crisp.
• Real-time play, like the original. The in-game clock follows your computer's clock, just as LovePlus+ followed the DS's. A Clock setting shifts it if your schedule doesn't match hers.
• Everything the DS had: the touch screen by mouse, buttons on the keyboard (rebindable) or a gamepad, the microphone for the moments she's listening, and closing the lid (minimize the window) to put the game to sleep.
• Your saves are ordinary files. Import a save from your cartridge or from DeSmuME (.sav / .dsv) and export it back.

Getting started

You need your own dump of LovePlus+ (Japanese release, game code BOXJ) as an .nds file. lp-engine includes nothing from the game: on first run it asks for your file and reads the game's data from it into its own folder. The .nds file is never modified.

Download the build for your system from Releases:

system	download	how to run
macOS 11+ (Apple silicon or Intel)	LovePlus+-…-macos.zip	unzip, move LovePlus+.app to Applications, open it
Windows 10/11 (64-bit)	LovePlus+-…-windows-x64.exe	run it, no installer (a portable single file)
Linux (x86-64)	loveplus_…_amd64.deb or LovePlus+-…-x86_64.AppImage	sudo apt install ./loveplus_…_amd64.deb, or chmod +x the AppImage and run it

The first start asks for your .nds file, then takes a few seconds to read it. After that the game starts straight away.

Controls

DS	default key
touch screen	mouse on the right-hand screen
A / B / X / Y	X / Z / S / A
L / R	Q / W
Start / Select	Enter / Backspace
D-pad	arrow keys

Keys can be changed under Controls, and gamepads work out of the box. View has the picture options, Sound the volume, output device and microphone, and Game the save import / export, the lid, the clock and the English / Japanese switch.

Where things are kept

Game data, saves and settings live in a per-user folder (Game > Show Game Folder opens it): ~/Library/Application Support/LovePlus+ on macOS, %APPDATA%\LovePlus+ on Windows and ~/.config/loveplus on Linux. Your save is saves/loveplus.sav.

Not supported

The wireless features (Talk Mode, card exchange, pass-by communication, save send / receive and transfer, regional capsules) need a second DS. Choosing one shows a short notice and takes you back to the menu.

Reporting a problem

Each play session is recorded quietly: the save it started from and your inputs, a few kilobytes. If the game's code ever stops, the recording is kept and the app tells you where. Attaching it to an issue lets the exact session be replayed, step for step. Turn on Game > Keep Session Recordings to keep them all.

Building from source

The engine is Rust (engine/); the tools around it are Python (tools/).

cd engine
cargo build --release --bin game
./target/release/game                 # as released: first run asks for your .nds file
./target/release/game ../content      # development: run from an extracted content folder

docs/RELEASE.md covers the release packages. The rest of docs/ is the reverse-engineering notes: the game's flow, script VM, save format, rendering, audio and more.

folder	what's in it
engine/	the engine and the game app (src/bin/game.rs), the extractor, the runtime, the renderer
translation/	the translation's working instructions; the translated text itself isn't published, only the delta in the releases
tools/	extraction, translation and packaging tools
docs/	notes on how the game works
sandbox/	experiments behind the engine's rendering and flow work

Legal

lp-engine is released under the MIT licence.

LovePlus is a trademark of Konami Digital Entertainment. This project is not affiliated with or endorsed by Konami or Nintendo. It contains no game code or assets: everything game-related is read from the player's own copy at run time, and the translation ships as a delta that applies only to that copy.

Voice playback uses an ITU-T G.722.1 Annex C decoder. Siren14™ / G.722.1C technology licensed from Polycom®, Inc. The third-party libraries the program is built with, and their licences, are listed under Help > Third-Party Notices.