QuestGun — Player's Guide

A virtual lightgun arcade cabinet for Meta Quest. Your Touch controller becomes an arcade gun, and the game plays on a large screen floating in front of you.

QuestGun is not an emulator and ships with no games. It loads emulator cores and game files that you supply — see Getting started.

There is one exception: a built-in demo range, a shooting gallery drawn by the app itself, so a fresh install has something to aim at before you have added anything. See Trying it without a game.

1. Quick reference

Credits are on both hands so you can add them without lowering the gun.

To reload, aim off the edge of the screen and pull the trigger, exactly as on a real cabinet. There is no reload button.

Starting a game — the bit everyone gets stuck on

Arcade machines take money. MAME faithfully emulates that, so a game will sit on its attract screen ignoring you until you pay.

1. Press Left X or Right B to insert a coin. Press two or three times for extra credits if you like.
2. Press Right A to start.

If nothing happens when you press A, you have no credits. Press coin again. This catches everybody at least once — the game looks like it is running, because the attract mode is running, but it is not listening for Start.

2. Getting started

What you need

• A Meta Quest headset with both Touch controllers
• An emulator core (see Supported cores)
• Game files you are legally entitled to use

You must supply your own game and BIOS files, from hardware you own. None are included and none are downloaded for you.

Where files go

Everything lives under the app's own folder, reachable over USB with no special permissions:

Android/data/com.questgun.arcade/files/
├── cores/     emulator cores (*.so)
├── roms/      your games
├── system/    BIOS files, if a core needs them
└── saves/     created for you

Copy files there with a USB cable and your computer's file browser, or with SideQuest's file manager.

Multi-file disc games — a .gdi or .cue refers to separate track files that must sit beside it. Give each of those games its own folder inside roms/:

roms/
├── mygame.zip                      a single-file game
└── My Disc Game/                   a disc game
    ├── My Disc Game.gdi
    └── My Disc Game (Track 1).bin

The menu shows the .gdi or .cue and hides the track files, which are not loadable on their own.

Choosing what runs

Open the menu (click either thumbstick), pick LOAD CORE, then LOAD ROM. That is all most people need.

To have something load automatically at startup, create a file called autoload.txt in the files/ folder:

core = mamearcade_libretro_android.so
rom = mygame.zip

3. Playing

The screen appears in front of you at launch. If it is off to one side, look straight ahead and press Left Y to recentre it.

Point the gun at the screen. A red laser dot shows where you are aiming, and your shots land there. The dot turns orange while the pedal is held.

Hold the gun like a pistol and aim down it. Do not try to line up the dot by moving your head — the gun's barrel is the aiming line, exactly as on a real cabinet.

If your shots land slightly off

This is normal and adjustable. Touch controllers held like a pistol tend to shoot a little high of where you think you are pointing.

Open the menu and adjust GUN PITCH (up/down) and GUN YAW (left/right) until the dot sits where you are actually aiming. Small values — a degree or two — are usually all it takes.

The menu

Click either thumbstick to open it. It appears to your gun-hand side, clear of the screen. Aim at it with the gun; the row under your aim highlights. Trigger selects, and either thumbstick left/right changes values (hold to repeat).

While the menu is open the game receives no input, so nothing is fired into it behind the panel.

The gun page

Everything about the gun lives behind GUN SETUP, so the main list stays short. < BACK returns.

If something is stuck

UNLOAD ALL is the way out of a bad state. It drops whatever core and game are loaded, clears the message on the screen, and leaves you at the idle panel with the menu open. Nothing on your headset is deleted — your cores and games stay exactly where they are.

Settings are not saved between launches yet.

Trying it without a game

Turn DEMO RANGE on in the menu and the screen becomes a tin can alley: bottles on a back rail, cans on a front one.

Bottles break and cans ring when you hit them, and the debris falls. Shoot everything and the range says so; the grip stands it all back up.

It is drawn and voiced by QuestGun itself — no core, no game files, nothing to install — so it works on a fresh install, and it is the quickest way to check that your aim is calibrated. If the laser dot sits on a bottle and the shot misses, your GUN PITCH and GUN YAW need trimming (they are under GUN SETUP); a hit means the aiming line and the dot agree.

The range only runs while no game is loaded. With a core running, the trigger and grip belong to the game as usual.

Quick adjustments without the menu

Hold Left grip and the sticks retune the setup directly. Nothing reaches the game while you hold it.

Full control list

Swap hands with GUN HAND in the menu; everything above mirrors.

4. Supported cores

Cores are not bundled. Download the Android arm64-v8a build of the core you want and copy it into cores/.

Match your games to your core

This is the most common cause of "the game will not load." MAME game files are tied to the MAME version a core was built from. A file built for current MAME will be rejected by an older core, and the reverse is equally true.

• mamearcade wants current MAME files
• mame2003-plus wants MAME 0.78-era files
• mame2010 wants MAME 0.139-era files

Short names can differ between MAME versions too, so the same game may be both the wrong contents and the wrong file name under a different core.

If a game will not load, try the same file under a different core before assuming the file is bad. LOAD CORE keeps your selected game and reloads it under the new core, so this takes seconds.

Flycast (Dreamcast and NAOMI) does not currently work

Dreamcast and NAOMI games load completely — BIOS, game, graphics and sound all initialise — and then the app closes as soon as the game starts running. This is a fault inside the Flycast core on this hardware, not something you have set up wrongly, and it happens with every Flycast build tested.

Use MAME instead. If a Flycast game does crash the app, the next launch skips it automatically and drops you into the menu rather than crashing again.

5. Troubleshooting

"Core rejected content" — the core has no driver for that game, or your game file is for a different MAME version. Try another core via LOAD CORE.

Nothing happens when I press Start — you have no credits. Press Left X or
Right B.

There are two aiming marks on screen — QuestGun hides MAME's own crosshair by writing a config file for each game the first time you load it, leaving just the red laser dot. If you have previously changed crosshair settings inside MAME's own menu, your file is kept and MAME's crosshair may still appear; delete system/mame/cfg/<game>.cfg and reload to get the default back.

The screen is off to one side — look straight ahead and press Left Y. If it is still slightly off, hold Left grip and nudge it with the right stick.

My shots land near, but not on, the target — adjust GUN PITCH and GUN YAW in the menu.

Shots land in the centre no matter where I aim — the core is not receiving the gun's position. Check you are using a supported core.

The ROM list is empty — files must be inside roms/. A disc game must be in its own folder with its .gdi or .cue beside its track files.

The app opened straight into the menu saying the last launch crashed — that is deliberate. The previous game brought the app down, so it started without loading anything. Pick something else, or use UNLOAD ALL to clear the message.

A message names a game I have removed — autoload.txt still points at it. QuestGun now ignores an autoload entry whose file is missing and starts empty instead, so this clears itself; UNLOAD ALL removes the message immediately. Edit or delete autoload.txt to stop it being looked for at all.

A message is stuck on the screen — UNLOAD ALL in the menu clears any message, along with whatever core and game are loaded. It deletes nothing from your headset.

6. What this app does not do

• It contains no games, no BIOS files and no emulator cores — the built-in demo range is the app's own artwork, not an emulated game
• It does not download anything for you
• It does not save your settings between launches yet
• It cannot make a game run faster than the headset's processor allows

Games that were designed for hardware far newer than the Quest's chip may load and still run too slowly to enjoy. That is a limit of the hardware, not a setting that can be changed.

← sludgesoft.github.io