FAQ

Comprehensive answers to common questions

General

What is this project?

The answer to this question is on the home page of our website:

A reimplementation of Cave Story engine with many quality-of-life improvements.

Please note that doukutsu-rs is not a decompilation, as it's written from scratch and does not contain the source code of the original game (unlike CSE2, which is actually a fan decompilation of a freeware executable).

doukutsu-rs was originally started as a Rust learning project and meme, but after a while it evolved into a drop-in replacement for the major editions of the game (the original 2004 freeware edition, Cave Story+ for PC and Cave Story+ for Switch).

Starting with version 0.99.0-beta1, released on January 16, 2022, the game is fully playable. Work is currently underway to further improve the engine and fix some discrepancies with the original game.

While doukutsu-rs tries to be faithful in behavior to the original game, it doesn't aim to be an exact copy of it. For example, doukutsu-rs lacks bugs that exist in the vanilla version of the game, so there are some differences in behavior (e.g. issue #278), but also includes features such as cutscene skip, lighting effects, subpixel scrolling and V-Sync support.

Also some features are not planned to be implemented such as Steam achievements, leaderboard, coop off-screen or floor particles in Sand Zone.

Where are the saves/settings/logs?

You can open the folder with saves and settings via the menu: Options -> Advanced -> Open user data directory.

If you created a portable user data directory, the saves will be in the user folder next to the doukutsu-rs executable.

Otherwise, the location of the user data depends on the platform:

• on Windows: %LOCALAPPDATA%\doukutsu-rs\data\ (that is AppData\Local\doukutsu-rs\data\)

• on macOS: ~/Library/Application Support/doukutsu-rs/saves

• on Linux:

  • if installed from Flatpak: $XDG_DATA_HOME/doukutsu-rs/ (usually this is $HOME/.var/app/io.github.doukutsu_rs.doukutsu-rs/data/doukutsu-rs/data)

  • if you downloaded the .elf executable file: $HOME/.local/share/doukutsu-rs/

• on Android: see How to open game/user data directory on Android?

The logs are stored in the logs folder next to the user data directory.

How to open game/user data directory on Android?

If you have an app on your device called Files (app id com.google.android.documentsui), open it, swipe from the left edge to the right (or press the ≡ menu icon) and select doukutsu-rs from the list. Saves will be in the saves folder, game data in the data folder, logs in the logs folder.

If there is no such application, then you can install shortcut for it and repeat with it the same actions described in the previous paragraph.

If you don't want to install this shortcut, then install Material Files (Google Play|F-Droid|Github Releases) by Hai Zhang. Once you open it, click on the menu icon ≡ -> Add storage -> External storage -> ≡ -> doukutsu-rs -> USE THIS FOLDER -> ALLOW. The files folder will appear in the menu, clicking on it will take you to the doukutsu-rs internal storage directory.

Features Support

Are the mods supported?

Shortly, doukutsu-rs doesn't support almost all Cave Story mods, including Jenka's Nightmare.

Only mods that modify game data files (textures, maps, text scripts, music, sounds) and don't modify the original game executable are supported. Cave Story+ mods and challenges are also supported, but there are graphics issues for some mods.

Is multiplayer supported?

Local co-op is available on PC, and starting with version 1.0.0, it's also available on Android.

Remote co-op (netplay) is not supported, and there are no plans to work on it in the near future.

Are saves from CS+ supported?

I copied the CS+ save file, but only the first slot is loaded/saved.

doukutsu-rs uses a freeware compatible save format, so each slot is stored in a separate file. Cave Story+ saves are stored in a single file, so doukutsu-rs only reads the first slot from this file, and writes only the first slot to it.

However, work on adding support for CS+ (PC, 2011) and CS+ Switch saves has already started.

Is a fixed window ratio (e.g. 4:3 as in the freeware) or resolution supported?

This feature is already present in one of the development branches, and it's expected to be added to the nightly and stable builds in one of the future releases.

Also this feature is implemented in the DrGlaucous's fork. However, it doesn't have prebuilts, so you'll have to build it from the source code. See Initial setup and compiling (don't forget to add the --release argument to cargo build).

Platform Support

Is controller supported on Android?

Support for controllers on Android was added in version 1.0.0.

Which platforms is doukutsu-rs available on?

doukutsu-rs is officially supported on PC (Windows 10+, Linux, macOS 10.12+) and Android 7+. Builds for these platforms are stable: release builds as well as nightly builds are available for them.

In addition, doukutsu-rs also has an experimental port for Nintendo Switch. Experimental ports may be unstable and lack certain features.

You should make a port to the XYZ platform.

doukutsu-rs is available on the most common platforms, so there are no plans to port to other platforms yet.

Although there are a number of unfinished experimental ports, specifically for iOS and UWP (Xbox), work on them is currently on hold.

The controls on Android are awkward, how do I customize them? How to make the buttons bigger or change their position?

No way. You cannot change the location of touch screen controls and their size. You can only disable their display in Options -> Controls -> Display touch controls -> OFF.

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Although you can try changing the size and position of the buttons in the source code and rebuild the executable file, but this is very inconvenient and will take some time to find the right values.

If you're ready for it, in the file src/input/touch_controls.rs on line 100-146 you can adjust the location of controls (the first argument of the add_rect_tinted function is an X-axis coordinate, and the second argument is a Y-axis coordinate), and in the file src/input/touch_player_controller.rs on line 81-239 you can adjust the zones for registering button presses (the zones in which the game will count pressing a particular button).

Game Info

What are the differences between the difficulty levels?

• Easy - damage dealt by enemies is halved.

• Hard - no life capsules and missile launcher.

How to activate seasonal textures?

They're used automatically if Graphics -> Seasonal textures option is enabled and the appropriate date has arrived.

• Christmas textures are active from December 24 through January 6.

• Halloween textures are active from October 26 through November 2.

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Still have questions?

Feel free to ask them on the project's Discord server or GitHub issues.