Brain Battle

Inspiration

We built Brain Battle to make revision more engaging and social. Instead of reading notes alone, we wanted a quick game where you can practice questions, see your progress right away, and play through it with friends.

What it does

Brain Battle is a retro-styled browser study RPG:

• You pick a boss (or run through All Bosses) and answer multiple-choice questions.
• Correct answers deal damage and earn coins/XP.
• Wrong answers cause the boss to attack.
• As you progress, you unlock features like the shop, daily quests, and a Pomodoro focus timer.
• You can customize content in-game via the Config Editor (create bosses, add questions, or generate questions from PDFs using Gemini).
• Optional multiplayer lobbies let players battle through boss lists together.

How we built it

• Built as a browser game using Vanilla JavaScript + HTML + CSS
• Vite for local development and builds
• Multiplayer uses WebSockets (ws) with a simple Node-based WebSocket server
• Question generation integrates Gemini, plus PDF parsing/chunking via pdfjs-dist
• Game progression/state and custom configuration are stored in the browser with localStorage

Challenges we ran into

• Balancing gameplay so the quiz loop feels fun (not punishing) while still rewarding skill
• Designing a flexible config system that supports both preset and user-created content
• Generating good quiz questions from PDFs reliably (format differences, chunking, prompt tuning)
• Keeping multiplayer simple and stable while still feeling responsive
• Managing a growing feature set (quests/shop/pomodoro/editor) without the UI becoming cluttered

Accomplishments that we're proud of

• A complete end-to-end gameplay loop that feels like a real “run” through bosses
• A working Config Editor that makes the game extendable without touching code
• PDF → question generation to help convert real study material into gameplay
• Optional multiplayer support (public/private lobbies + host-controlled boss lists)
• Multiple progression systems (XP/levels, coins, unlocks) tied into the core learning loop

What we learned

• How much UX matters in learning tools—tiny feedback loops (damage numbers, coins, animations) make studying feel rewarding
• Better understanding of real-time communication tradeoffs and WebSocket architecture
• Prompting and preprocessing matter a lot when generating usable questions from messy documents
• Building a hackathon project is as much about cutting scope wisely as it is about building features

What's next for Brain Battle

• More boss variety and question categories (and better difficulty scaling)
• Better multiplayer modes (co-op events, competitive leaderboards, seasonal runs)
• Accounts / cloud sync for progress and custom content (instead of only localStorage)
• Improved question generation quality controls (review/edit flow, duplicate detection, difficulty tagging)
• Mobile-friendly UI polish and accessibility improvements

Built With

• css
• gemini
• html
• javascript
• railway
• vite
• websockets