Hasumi has always felt more at home beneath the waves than above them. While other teenagers scroll through social media, she free-dives among coral reefs, listening to the ocean’s forgotten hum. But lately, the hum has turned into a cry.
Strange things are happening: bioluminescent algae bloom in the shape of warning runes, fishing nets pull up skeletal sea dragons, and a low-frequency drone drives marine life ashore. Then one night, a pearl-colored scale washes up at Hasumi’s feet, glowing with a voice:
"Mermaiden… the abyss stirs. Find the Sisters before the silence takes everything." Mission Mermaiden - Hasumi and the Deep Sea Sis...
The core of Mission Mermaiden is its underwater traversal. Unlike typical platformers where water levels are often considered a nuisance due to sluggish controls, this game embraces the environment.
Act I – Descent
Hasumi accepts “Mission Mermaiden” after being promised answers about her sister’s disappearance. She descends to the Midnight Zone (2000m) and first encounters the Sisters — mistaking their defensive postures for aggression. Hasumi has always felt more at home beneath
Act II – Resonance
After a near‑fatal equipment failure, a young Sister named Lumina saves Hasumi. Through shared visions (triggered by a symbiotic kiss / pressure‑touch), Hasumi learns the Sisters hold her sister’s memories. The “enemy” is not the Sisters but the mining fleet above.
Act III – Uprising
Hasumi and the Sisters sabotage the mining operation using acoustic resonance (whale‑song cannons). Hasumi’s sister’s memory‑pearl is retrieved, revealing she chose to become part of the Sis collective. Hasumi stays as a surface liaison, renaming the mission “Guardian Mermaiden.” "Mermaiden… the abyss stirs
Genre: Action RPG / Metroidvania / Indie Developer: Sekai Project (and related indie circles) Theme: Underwater Fantasy, Transformation, Sci-Fi
The "Deep Sea Sisters" are not generic bosses. Each sister represents a different aspect of oceanic peril, requiring unique strategies to pacify.