Is Leviathan Worth Reading? Review & Where to Read

Overview

Seventy years of endless rain finally drowned the world. An icy comet collided with the moon, triggering a catastrophic flood that submerged the entire planet, and what's left of humanity survives on the open ocean, scavenging a submerged planet, while the sea itself has turned against them: creatures mutated by the flood into monstrous "leviathans" now hunt anything that swims or sails. When their father dies saving them from one such monster, siblings Bota and Rita are taken in by a woman named Kana, and thrown into a life defined by scarcity, violence, and the constant threat of the deep.

What it does well

The premise-first appeal is real: a fully drowned Earth is a striking, rarely used disaster-horror setting, and the manhwa commits to it, ships and floating settlements standing in for cities, leviathans replacing every other kind of apocalypse monster. Writer Lee Gyuntak and artist Noh Miyoung build out that world with real consistency, and the sibling bond at the center gives the survival plot real emotional grounding — Bota and Rita's relationship, and their found family with Kana, carries the story through its bleakest stretches.

Noh Miyoung's art handles both the horror of the leviathans and the scale of the flooded world well, and the full-color presentation gives the ocean setting real atmosphere. The supporting cast around Kana's found family also gets real attention rather than staying purely functional, which helps the story's quieter chapters land alongside its horror set pieces. Backed by strong, consistent ratings — including scores in the 8-out-of-10 range across major tracking sites — and a large readership across both its original Korean run and English release, it's clearly landed with survival-horror fans, with at least one detailed reader review calling it a gritty, well-paced, and genuinely immersive post-apocalyptic epic.

Where it falls short

This is a Mature-rated series, and the blood, gore, and threat level are genuinely heavy throughout, not for readers who want their monster-survival stories softened. The English WEBTOON release is also still catching up week by week even though the original Korean series is already complete, so newer content arrives on a weekly schedule rather than being available all at once. And the sheer bleakness of a fully drowned world, one where losing people is a constant, will be a lot for readers who want more hope woven through their disaster fiction.

Verdict

If a genuinely dark, well-drawn monster-survival story set in a fully submerged world sounds appealing, this delivers on that premise with real emotional stakes underneath the horror. It's grim and heavy by design, but it earns that tone rather than using it for shock value.