Bean Bash

A Fall Guys–style trivia game for our events. The projector shows a 3D arena; the audience joins on their phones by scanning a QR code. Each question, you drag your bean onto one of four answer platforms before the timer ends. The wrong platforms drop away and those beans fall. Last bean standing wins.

One round type, on purpose. Nobody needs instructions, and a new group can be playing within a minute.

Host from https://gdg-bean-bash.advancelabs.workers.dev/arena.html — use this exact URL, full-screen, on the laptop driving the projector.

Players join at https://gdg.runs-on.dev (or the same workers.dev domain, /) — the arena's QR code and join link already point at the right place, so nobody needs to type a URL.

gdg.runs-on.dev is a friendly redirect (via Advance Labs' runs-on.dev) to the deployment above, but it only redirects the bare root — it can't reach /arena.html or /screen.html, and it drops query strings (so ?room=CODE links don't survive it either). That's a deliberate limitation of runs-on.dev's registry, not a bug: a claimed name redirects exactly one URL, nothing path-aware. Always use the workers.dev URL directly for hosting or for a specific room link; use gdg.runs-on.dev only as the memorable "type this in your phone's browser" fallback for the plain join screen.

Colors, typography, and the GDG attribution/disclaimer footer on every screen follow the GDG on Campus brand kit.

Running the night of the event

1. Open the arena page on the laptop driving the projector and put it full screen.
2. The page shows a QR code and a 4-letter room code. Leave it up while people arrive and eat.
3. Press S to start. Questions last 20 seconds, then a 6-second reveal.
4. Keep the browser tab open. Reloading is safe (the room is in the URL), but closing it ends the room.

Host keys on the arena page:

Key	What it does
S	Start a game
N or space	Skip to the next question
R	Revive everyone, so knocked-out players are back in
Esc	New game, back to the lobby
M	Mute or unmute the sound

The same buttons are along the bottom of the screen if you'd rather click.

Music. A four-bar loop plays under everything: calm in the lobby, faster with drums while a question is running, and it dips under the fanfares and the platform collapse. It starts on the first press of S along with the rest of the audio, and M mutes it too.

Sound. The arena plays its own sound effects: a blip when someone joins, a fanfare when a question starts, a countdown in the last 5 seconds, a rumble as the wrong platforms drop, and a win or wipeout sting at the end. Plug the laptop into the room speakers. Browsers only allow sound after a click, so the first press of S switches it on. Press M or the Sound button to mute; the choice is remembered on that laptop. Phones stay silent on purpose, so 20 phones don't blare at once.

Run it in short bursts. Eight to ten questions takes about eight minutes. Run a game while people arrive, another after the team intros, and a final one for a prize. Anyone who arrives mid-game is marked as waiting and joins the next one.

Editing the questions

Questions live in src/questions.json. Each one has the question text, four answers, and correct as the index of the right answer (0 is the first answer, 3 is the last).

{
  "text": "What does the 'G' in GDG stand for?",
  "answers": ["Great", "Google", "Global", "Graduate"],
  "correct": 1
}

Keep answers short: they are printed on the platforms. Mix easy and silly ones so students who don't code still have fun. Questions are shuffled every game.

Running it on your own machine

npx wrangler dev

Then open http://localhost:8787/arena.html for the screen and http://localhost:8787/ for a phone. Phones on other devices can't reach localhost, so test a real crowd against the deployed version.

Deploying

The game runs on Cloudflare Workers, which is free at our size. First time on a new machine:

npx wrangler login

Then, from this folder:

npx wrangler deploy

Wrangler prints the URL — it's tied to whichever Cloudflare account is logged in (each account has its own *.workers.dev subdomain), so deploying from a new machine/account gives a new URL, not an update to the old one. If that happens, update the gdg.runs-on.dev redirect at runs-on.dev/manage (or edit domains/gdg.json in the runs-on.dev repo) so the QR code keeps working without reprinting anything.

How it works

Piece	What it does
src/server.js	The room. One Durable Object per room code, holding players, the current question, and the timer. It is the only thing that decides who is knocked out.
public/arena.html, public/arena.js	The projector view. 3D arena, beans, QR code, host controls.
public/index.html, public/phone.js	The phone. Join, pick a colour, drag your bean.
public/audio.js	The sound effects and the background music, synthesised in the browser. No audio files, nothing to download.
public/screen.html, public/screen.js	A flat 2D version of the screen. Backup if 3D misbehaves on the venue laptop.
src/questions.json	The questions.

Phones send where their bean is standing, ten times a second. The server works out which platform that is, and the correct answer never leaves the server until the reveal, so nobody can peek by opening the developer console.

If something goes wrong

• Phones can't join. Check that the QR code points at the deployed URL and not at localhost.
• The 3D arena is slow on the venue laptop. Use /screen.html instead. Same game, flat 2D, much lighter.
• Everyone is knocked out at once. Press R to revive them all and keep going.
• No sound. Press S once (browsers block sound until a click), check the Sound button in the corner does not say "Sound off", and check the laptop's own volume and output device.
• The whole thing misbehaves. Have a Kahoot with the same questions ready and switch. Nobody will mind.