水槽から外洋まで進む3D魚サバイバルゲーム

Build a fully 3D browser game in which the player is a small fish that eats, grows and avoids predators. Structure it as five chapters: a home aquarium, a garden pond, a flowing river, a coral reef and the open ocean. Use a soft low-poly look with teal and green water, tinted light shafts, rounded rocks, plants, coral and drifting particles. Third-person camera follows the fish. Controls: swim with keyboard or mouse, eat smaller creatures to grow in size, dodge larger fish and hazards that shrink you. Add a clean HUD with the fish name, current length, a growth bar, a small radar and chapter title cards with short hint lines. Ship it as a self-contained web project using Three.js that runs in a browser. Done means all five levels are reachable in order, growth changes what you can eat, and a full run from aquarium to ocean is playable.