Deep Sea Guardians: recruit, merge and defend the reef.
Deep Sea Guardians is an HTML5 merge tower defense template with full source code, set under the sea. Recruit little sea guardians, drag two equal guardians together to grow a stronger one, and place your best guardians in the front slots so they shoot at the pirate submarines heading for the reef barrier. Easy to start, with real decisions later: which guardians to merge, when to call the next wave and what to buy in the Reef Base.
12 sea guardians, each with its own attack
From a clownfish blowing bubbles to a sea turtle lobbing shells, a frost seahorse, an electric ray, a narwhal lance and a royal octopus whirlpool. Merge two equal guardians to reach the next level; merge combos pay a bonus.
30 waves, 3 worlds and 3 bosses
Sunny Reef, Sunken Ruins and Luminous Abyss, with 8 kinds of pirate submarines and a boss every 10 waves (Ram Submarine, Deep Sea Corsair, Abyssal Driller), each with its own entrance and boss music. After the campaign, Endless mode keeps going.
Juicy, and kind to the player
Shot trails, merge bursts, flying coins and boss entrances, all tuned in one file. A first-game tutorial with the octopus captain, retry that resets the wave when the barrier falls, Fish School and Current powers, bonus drops, 1x/2x speed, and calmer effects when the system reduce-motion setting is on.
Your game, your hosting
Upload the contents of the game folder to static HTTP(S) hosting. No PHP, database, account or Node.js is needed on the server, and the game makes no requests to ranking, advertising, tracking or payment services. Landscape layout for phones, tablets, desktop and ultrawide screens, with mouse, touch and keyboard.
What this edition does not include
Native apps, hosting and custom development are not included, nor are cloud saves, an online ranking, real-money purchases or an advertising SDK.
Who this template is for
Site and portal owners who want a friendly ocean strategy game, freelancers and studios building a branded game for a client, and developers who want readable plain JavaScript to learn from or reskin.
Customise it
All balance numbers live in src/game/data.js (guardians, enemies, waves, bosses, prices, rewards) and all game-feel numbers in src/render/feel.js. All player-facing names are in the texts in src/i18n/. The engine is shared with a garden-themed template, so some internal code keys keep neutral names; the README maps each one to its sea name.
Technical details at a glance
- Stack: HTML5, plain JavaScript ES modules (no compile step), Canvas 2D and Web Audio.
- 14 interface languages; offline illustrated guide in English, Portuguese and Spanish.
- Node.js 26.13+ only for the optional tools: tests, build copy and local server.
- Local Fredoka font with its OFL licence; no third-party code in the game.
