About
Hydra Castle Labyrinth (originally Meikyuujou Hydra) is a freeware action-platformer metroidvania by Japanese developer E. Hashimoto, known as Buster. You play a knight exploring the Hydra's sprawling castle to recover a stolen royal crown, gaining new powers and clearing sub-dungeons along the way. Inspired by The Maze of Galious and La-Mulana, it is more approachable than either, and it built a cult following among fans after an English fan-translation patch made the originally Japanese-only release accessible worldwide. It was distributed free on the developer's own site and never sold commercially, which is why it has no Steam page.
Identity
Launch
- Binary
- hydra.exe
- Needs files
- none beyond the binary
Proton
- Version
- GE-Proton
- Winetricks
- —
⚙ Setup notes
Game: E. Hashimoto's (Buster) 2011 freeware action-platformer metroidvania, with Gary the Krampus's English translation patch. Tiny self-contained SDL Windows app — no installer.
Proton: Runs under Proton with GE-Proton; proton_experimental also works.
DRM: No DRM, no GFWL.
Controller: The game has built-in joypad support, but button mapping is done through the bundled IniKaeru config tool (ships with the download), not auto-detected. On the Deck the most reliable path is a Steam Input controller layout (keyboard mapping) — the documented keys are arrows (D-pad), SPACE (attack), E (jump), F (throw), S/D (prev/next weapon), TAB (items), ENTER/ESC (pause). You can instead map a joypad via IniKaeru if you prefer.
Install: The English patch swaps in its own hydra.exe (built for v1.00) — keep that as the launch target. The patched .exe is the right binary to point Steam at; do not aim Proton at the Japanese v1.03 build if you applied the patch.
The one thing to know
Supply your own copy: Freeware game (never sold on Steam, so no appid) with a fan English patch — the patch replaces hydra.exe (built for v1.00, still works).
Proton: No DRM/GFWL, so it runs cleanly under Proton. Built-in joypad support exists but is mapped via the bundled IniKaeru tool; a Steam Input keyboard layout is the simplest way to get the Deck's controls working.
Display: Known quirk (Windows + Wine/Proton) — the game window can spawn offset toward the right edge of the screen rather than centered. Cosmetic, not game-breaking; if it lands off-screen, force Borderless/Fullscreen via the in-game options or relaunch.
Native option: A native Linux/SDL port also exists (ptitSeb) if you'd rather skip Proton entirely.
Community guides
Write-ups and threads from people who got this (or a similar) game running. deckport links to them — it doesn't reproduce them.
Get the artwork
deckport never hosts game images. Open this game on SteamGridDB, pick
the cover / hero / logo / icon you like, and drop them into the
game folder under .deckport-art/ before you push it to the
Deck. The importer files them under the right names automatically.
Run it on your Deck
Two files: the one-time importer (deckport.py) in your
Deck's home folder, and this game's install helper. Copy the game
into ~/Games and run the helper with Steam closed — it
writes the recipe (binary, launch options, Proton version)
and registers the shortcut with artwork.