LEVIATHAN — WORLD & OVERVIEW

Leviathan · Evolve the Deep is a one-tap merge-and-evolve game set in a single living reef. You drop fish into the water from the top of the tank; two of the same species touch and merge into the next species up the ladder. Climb all eleven species — from a humble Fry to the legendary Cosmic Whale — inside one continuous, beautifully animated ocean.

The fantasy

The reef is yours to raise. Every drop sends a fish darting off with its own personality, trailing bubbles through drifting currents and shafts of sunlight. Life begets greater life: match, merge, and watch the deep evolve under your hands until a Leviathan rises and, finally, the Cosmic Whale is summoned.

The core loop

1. Aim along the top of the tank and tap to drop the next fish.
2. Matching species merge on contact into the next tier, paying pearls.
3. Spend pearls in the Reef Shop on eggs (spawn fish), tank capacity, and boosts.
4. Survive the Spikefish — a prowling threat that nets you pearls if you tap it in time.
5. Goal: raise two Leviathans and merge them to summon the Cosmic Whale — the win. Then begin a new reef.

Pillars

• Instantly readable, endlessly watchable. One verb (drop). The spectacle — swimming AI, mutations, currents, caustic light — does the rest.
• Relaxing but not idle. Calm to learn; the Spikefish and tank-capacity pressure keep hands busy.
• Always a reachable goal. The next species is always visible on the ladder; the headline goal (2 Leviathans) is stated on screen at all times.
• Premium, never slop. Procedural sprites, per-fish personality, a real light system, and a rewarding victory sequence.

Platform & status

• Status: shipped (CrazyGames, Full launch — SDK + ads).
• Tech: single self-contained HTML5 file; Matter.js physics (inlined); Web Audio + mp3 beds; CrazyGames SDK v3.
• Orientation: portrait-first, scales across all portal ratios.
• Play: Leviathan · How to play

Where to go next

• The 11 Species — the full evolution ladder.
• Core Mechanics — dropping, merging, capacity, the two-plane depth.
• Pearls & Economy — currency, the Reef Shop, rewarded boosts.
• Mutations & Traits — the five rare bloodlines and their prizes.
• The Spikefish Threat — the reef's one predator and how to beat it.