@Drahsid Thank you for this! I've set TIMEBEFOREEXECUTE to 0 and the game doesn't softlock in the main menu for me. Any way I can change the initial mouse state to locked?

Here are detailed instructions for anyone having trouble:
- Download newest Win32 Mupen64Plus release (I used v2.5.9) and extract it to the folder of your choice ("GameDir" from now on).
- Download Drahsid's Mouse Input Patch, extract it to the GameDir and overwrite.
- Place the game ROM into the GameDir.
- Start the game (by dragging and dropping ROM file onto mupen64plus-ui-console.exe) to generate the config file and close it.
- If you get "Core Error: incompatible Input plugin" crash (I did) download Drahsid's Mupen64Plus SDL Input Plugin v2.5.9 Patch, extract it to the GameDir and overwrite.
- To run the game in fullscreen and FullHD edit %appdata%\Mupen64Plus\mupen64plus.cfg and under [Video-General] set Fullscreen to True, ScreenWidth to 1920, and ScreenHeight to 1080.
- If you prefer pixelated textures over blurry ones edit mupen64plus.cfg and under [Video-Rice] set ForceTextureFilter to 1.
- Start the game and spam Enter (also hold F) until you are in control of the character; use the Home button to lock/unlock the mouse (activate/deactivate the script).
- If your game freezes upon character selection, either restart the game and try again as that seems to be random, or edit mupen64plus.cfg and under [Core] set R4300Emulator to 0 as suggested by Drahsid.
- While in-game: Enter > Options > Display > Resolution > Letterbox.

Playing with optional Glide64mk2 video plugin:
- Edit mupen64plus.cfg and under [UI-Console] set VideoPlugin to "mupen64plus-video-glide64mk2.dll".
- Start the game to generate [Video-Glide64mk2] section in the config file.
- Edit mupen64plus.cfg and under [Video-Glide64mk2] set aspect to 2.
- If you prefer pixelated textures over blurry ones under [Video-Glide64mk2] set filtering to 2.
- While in-game: Enter > Options > Display > Resolution > Letterbox.

Playing with optional GLideN64 video plugin:
- This plugin seems to give the best results but has no point-sampled/nearest-neighbor (pixelated) filtering as of this writing.
- Download newest GLideN64 release (I used v4.0), open it and extract the contents of bin\Mupen64Plus\ to the GameDir.
- Edit mupen64plus.cfg and under [UI-Console] set VideoPlugin to "mupen64plus-video-GLideN64.dll".
- Start the game to generate [Video-GLideN64] section in the config file.
- If you get a frozen SDL_app window upon start (might happen with newest GLideN64 built from master) edit mupen64plus.cfg and under [Video-GLideN64] set ThreadedVideo to False.
- Edit mupen64plus.cfg and under [Video-GLideN64] set AspectRatio to 3.
- To remove the black bars around the game under [Video-GLideN64] set EnableOverscan to True, OverscanNtscLeft, and OverscanNtscRight to 32, OverscanNtscTop and OverscanNtscBottom to 16.
- While in-game: Enter > Options > Display > Resolution > High.

Setting up the controls:
- To get WASD movement, while in-game: Enter > Options > Control > Style > Normal left-handed.
- To turn off automatic aiming: Enter > Options > Control > Auto Aim > No.
- To make Fast-forward your Left-shift running edit mupen64plus.cfg and under [CoreEvents] set Kbd Mapping Fast Forward to 304.
- To disable the keys that terminate/freeze the game under [CoreEvents] set Kbd Mapping Stop, Kbd Mapping Reset, Kbd Mapping Pause, and Kbd Mapping Frame Advance to "".
- Under [Input-SDL-Control1] set the keysyms as follows:
mode = 0 // Custom controller configuration.
Z Trig = "mouse(1)" // Attack/Fire to Left-click.
B Button = "key(113)" // Next-weapon/Use to E.
A Button = "key(101)" // Previous-weapon to Q.
C Button R = "mouse(3)" // Scope-on/Scope-off to Right-click.
C Button D = "key(306)" // Crouch to Left-ctrl.
L Trig = "key(32)" // Jump to Spacebar.

Making the game portable:
- Copy %appdata%\Mupen64Plus\mupen64plus.cfg to the GameDir.
- Edit mupen64plus.cfg (in the GameDir) and under [Core] set ScreenshotPath to "screenshot", SaveStatePath to "save", SaveSRAMPath to "save", and SharedDataPath to "shared".
- Copy the code below into Notepad and save it into the GameDir as play.bat.
for /f "tokens=*" %%a in ('dir /b *.z64') do mupen64plus-ui-console.exe --configdir .\ "%%a"
- Use play.bat to start the game (script assumes ROM file has .z64 extension).