About Reefroit
The free browser cell eating game — eat, grow, evolve, and dominate.
What is Reefroit?
Reefroit is a free, browser-based io game in the cell eating genre. You control a single cell in a large ocean arena filled with food pellets and AI-controlled opponents. The objective is simple: grow as large as possible by consuming everything smaller than you while avoiding anything bigger.
Reefroit is inspired by classics like agar.io but built from scratch with extra mechanics that make each session more engaging — an evolution tier system, kill-streak combos, a respawn mechanic, boss arena events, and a live chat atmosphere powered by smart bot AI. No accounts, no downloads — just click and play.
Evolution Tier System
One of Reefroit's defining features is the 5-tier evolution system. As your cell grows in mass, you automatically evolve into a new creature with a different visual identity. Reaching each new tier triggers an on-screen notification and changes how you appear on the leaderboard and above your cell in the arena.
| Tier | Name | Mass Required | Description |
|---|---|---|---|
| 1 | 🐟 Minnow | Starting | Fresh spawn — learn the arena and eat food pellets to grow. |
| 2 | 🐠 Tuna | 600+ | You're a real threat to smaller cells now. Start hunting. |
| 3 | 🐬 Dolphin | 2,000+ | Mid-game power — use viruses and splitting strategically. |
| 4 | 🐋 Orca | 7,000+ | Apex predator territory. Most cells will flee on sight. |
| 5 | 🐳 Whale | 20,000+ | Maximum evolution. You dominate the arena — until the boss arrives. |
Kill-Streak Combos
Eliminate multiple opponents in quick succession to trigger escalating combo bonuses displayed on your screen. These combos reward aggressive, skillful play and multiply your score:
- COMBO ×2 — 2 kills within 6 seconds
- TRIPLE KILL! — 3 kills in a streak
- RAMPAGE ×4 — 4 consecutive kills
- 🔥 FEEDING FRENZY! — 5 or more kills in a streak
Respawn Mechanic
Unlike most io games where death means starting over from nothing, Reefroit gives you one respawn per session. When you're eliminated for the first time, a 3-second countdown begins and you re-enter the arena with 40% of your last mass — enough to continue the fight rather than rebuilding from scratch. Your second death ends the session.
Boss Arena Events
Every 4 minutes, a colossal 🦈 Megalodon entity spawns into the arena — three times larger than the current biggest player. The activity ticker announces its arrival and bots react with panic chat messages. Surviving while the boss hunts the arena is a challenge in itself; eliminating it rewards a massive score boost.
Virus Mechanics
Green spiked virus entities are permanent hazards scattered across the arena. If your cell is large enough to overlap a virus, you split into smaller fragments. Unlike some io games, viruses in Reefroit never disappear — they're always where you left them, rewarding players who memorise their positions. Split cells re-attract and merge automatically after an 8-second cooldown.
How It Was Built
Reefroit is built entirely with vanilla JavaScript and HTML5 Canvas — no game engine, no external dependencies in the core gameplay loop. The architecture has three clean layers:
- Shared Game Engine — physics, collision detection via quadtree spatial indexing, and multi-personality bot AI. Runs identically in the browser and (future) Node.js server.
- Bot Game Client — runs the full engine client-side for instant offline play. Simulates a live multiplayer atmosphere with bots, a live leaderboard, chat, and ticker events.
- Multiplayer Layer (planned) — server-authoritative real-time PvP via WebSockets. The codebase is already structured to support it without major rewrites.
The project is bundled with Vite for fast development and optimised production builds with multi-page SEO support.
Mobile Support
Reefroit runs in any modern mobile browser. Touch devices automatically display a virtual joystick — tap anywhere on the left half of the screen to summon it. On-screen SPLIT and W buttons appear on the right side for one-handed play. No app download required.
What's Next?
The immediate focus is polishing the single-player bot experience. Planned additions include power-up pellets (speed boosts, shields, score multipliers), new game modes, additional bot personalities, and real-time PvP multiplayer — the codebase already supports it structurally.