Avatar Arena

Avatars attack! Battle your friends in this turn-based combat simulation game. https://www.reddit.com/r/AvatarsArena/comments/1ojnnxn/avatar_arena/

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Avatar Arena

A Reddit-integrated turn-based battle game built with Unity + Devvit
▶ Play Now on r/AvatarsArena

Inspiration

Reddit’s avatar community (like r/AvatarTrading) is one of the most creative corners of the platform — full of users showing off, customizing, and trading their digital identities.

We wanted to turn that energy into something interactive: what if you could actually battle using your Reddit avatar?

Avatar Arena was born from that question — combining community identity, creative expression, and game design into a quick, satisfying turn-based experience built entirely for Reddit.

What It Does

Avatar Arena lets Redditors bring their avatars to life and fight community opponents. Each enemy is a real Reddit user — artists, staff, and known accounts from across the site.

Players can:

  • ⚔️ Battle across 3 difficulty levels (Easy / Medium / Hard)
  • 💰 Earn XP and gold from victories
  • 🧩 Level up to boost stats and unlock stronger attacks
  • ⚡ Use the SP (Strategic Points) system to unleash special moves
  • 🧠 Preview and reroll enemies, viewing their stats and rewards
  • 🧍‍♂️ Fight real Reddit avatars — pulled directly from Reddit’s API

Every match is quick, strategic, and personal — your Reddit identity becomes your fighter.

How We Built It

🎮 Frontend (Unity WebGL)

  • Built the battle system and UI in Unity
  • Integrated LeanTween for smooth animations and timing
  • Designed a responsive, mobile-friendly layout optimized for Reddit embeds
  • Added dynamic damage text, turn indicators, and attack feedback for polish

🌐 Backend (Devvit + Express.js + Redis)

  • Devvit powers Reddit authentication and avatar retrieval
  • Express.js server handles battle logic, XP, and persistence
  • Redis stores user progression, stats, and gold
  • Implemented retry logic with exponential backoff to prevent authentication failures (401s) from interrupting gameplay

🤖 AI-Accelerated Development (Kiro)

We developed alongside Kiro, an AI coding assistant that served as our “pair programmer.”
Kiro helped us:

  • Scaffold and debug Unity ↔ JS ↔ Node.js communication layers
  • Auto-generate API test panels and mock data systems
  • Iterate rapidly on battle balance and difficulty curves
  • Generate and format documentation

Kiro became an integral co-developer throughout the hackathon — accelerating iteration while letting us focus on creativity and balance.

Core Game Systems

⚔️ Battle Mechanics

  • 4 Actions: Attack, Defend, Special, Heal
  • SP (Strategic Points) govern special moves
  • Balanced pacing for 3–7 turn battles
  • Randomized damage adds variety to each round

🎚️ Difficulty System

  • Easy / Medium / Hard modes affect:
    • Enemy HP and attack power
    • Gold and XP rewards
    • Risk level indicators (Low / Balanced / High)
  • Reroll system for new opponents

🧍‍♀️ Player Progression

  • Persistent stats via Redis: level, gold, XP
  • Level-ups increase HP, SP, and attack stats
  • Gold can be spent on upgrades in future updates

🖼️ Avatar Integration

  • Pulls Reddit avatars directly from the Reddit API
  • Implements cache-busting for up-to-date visuals
  • Supports fallback for users without custom avatars
  • Real-time avatar swapping in battles and menus

Challenges We Ran Into

🔧 Technical Integration Challenges

Unity ↔ JavaScript ↔ Server Communication
Creating a seamless three-layer communication system required precision. We learned to handle UTF8ToString conversions carefully and standardize naming conventions to avoid data mismatches.

Authentication & Session Management
Expired JWT tokens occasionally broke the flow — we solved it by adding transparent retry logic with exponential backoff. The player never sees an error; it just works.

⚔️ Game Balance & Pacing

Our first battles dragged on for up to 12 turns!
Through iterative tuning, we refined formulas until we hit the sweet spot:

  • Easy: 3–4 turns
  • Medium: 4–6 turns
  • Hard: 6–8 turns

🎨 UX and Animation Flow

Coordinating animations, text feedback, and UI transitions without overwhelming the player took fine-tuning.
We learned that animation timing and easing can make or break immersion.

📊 Data Architecture

We decided to curate 65+ “real Reddit users” as enemies — recognizable avatars that feel meaningful to battle. Curated content provided a stronger connection than procedurally generated foes.

Accomplishments We’re Proud Of

  • 🚀 Fully playable MVP deployed directly on Reddit
  • 🎮 Integrated Unity WebGL + Devvit + Redis into one ecosystem
  • 👥 65+ curated community avatars as opponents
  • 🧠 Balanced, responsive, mobile-friendly gameplay
  • 🤖 Successfully used Kiro AI for full-stack collaboration — from idea to polish

What We Learned

We learned that community-first design is key to Reddit-based projects — and that AI can be a true co-pilot when managed thoughtfully.

From a technical perspective:

  • AI collaboration + version control = power combo.
    Kiro was used for everything: scripting, testing, iteration, debugging, and documentation.
  • Iterative balance > theoretical optimization.
    Real playtesting led to better pacing than formulas did.
  • Error handling is part of UX.
    Retry logic and fail-safes improved experience more than any new feature.
  • Platform constraints drive creativity.
    Devvit’s sandbox pushed us to find elegant, minimal solutions.

In short: AI helped us think faster — but design discipline kept the project human.
With good version tracking and human review, tools like Kiro can be essential for future hackathon-scale projects.

What’s Next

  • 🧩 Inventory system & item shop
  • 🏆 Player-vs-Player battles
  • 🧑‍🤝‍🧑 Community tournaments and leaderboards
  • 🪄 Special events for Reddit avatar artists
  • 📱 Full mobile optimization

We’re excited to keep expanding Avatar Arena into a fully community-driven experience — a game built by Redditors, for Redditors.

🔗 Links

Play now: https://www.reddit.com/r/AvatarsArena/
Built for: Community Games 2025 Hackathon
Tech Stack: Unity WebGL · Devvit · Express.js · Redis · TypeScript · LeanTween

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