Mission Mermaiden ~Hasumi and the Deep Sea Sisters~ is an adult action-platformer (eroge) released in 2020 by developer Mizunashi-tei (or Mizunashitei). Set in a post-apocalyptic future, it follows a female protagonist battling alien life forms. Game Overview Genre: Action, Side-scroller, Platformer. Rating: 18+ (NSFW/Adult content). Release Date: July 27, 2020. Platform: PC. Plot & Setting
In the year 2101 AD, Earth has been ravaged by an alien invasion. The protagonist, Hasumi Shiori, is a newly official member of the military after successfully dealing with a previous meteor disaster. She is sent to the Karimantan Jungle on a secret mission to confirm the existence of a rumored bioweapon and investigate strange life forms.
During her investigation, she must thwart the plans of the Deep Sea Sisters, mysterious adversaries who use hypnosis, experimental substances, and technical devices to manipulate their targets. Key Characters
Hasumi Shiori (蓮見 栞): The main heroine. She is described as straightforward, passionate, and brave.
Marco: An intelligent machine and returning character from the previous title who provides communication and tactical support.
Minegishi: A researcher at the rest area who acts as a "reliable older sister" figure, providing intelligence and logistics.
Saki & Mari: Mysterious girls who appear during the investigation; Saki is sharp-tongued and youthful, while Mari is mature and composed. Gameplay Features Mission Mermaiden - Hasumi and the Deep Sea Sis...
Transformation System: Hasumi can transform when her Energy gauge is full, which increases her attack and defense and clears most negative status effects.
Resource Management: The game features "Willpower," "Pleasure," and "Corruption" meters that track the character's state and influence the story's outcome.
Combat: Players engage in 2D platforming battles with 12 unique enemy types and 6 boss fights.
Modding Community: A notable mod titled "The Downfall of Hasumi" exists, which reworks the AI, status effects, and resource management to create a more challenging experience. 🌊 Pro-Tip for Players
If you are playing the modded version, be aware that it replaces the standard Health system with a "Willpower" system, making status effects much harder to undo and more impactful on gameplay. If you'd like, I can: Help you find walkthroughs for specific stages.
Detail the installation steps for the popular gameplay mods. Explain the different endings and how to unlock them. Let me know how you want to dive deeper into this game! Mission Mermaiden - The Downfall of Hasumi by NoGag Mission Mermaiden ~Hasumi and the Deep Sea Sisters~
Mission Mermaiden - Hasumi and the Deep Sea Sisters (also known as The Downfall of Hasumi) is a 2D side-scrolling action platformer released in July 2020.
The game features several core gameplay mechanics and "features" typical of its genre:
Story Mode: Set in 2101 AD, you control Hasumi, who is sent to the Karimantan Jungle in a post-invasion world to investigate a rumored bioweapon.
Combat Mechanics: Includes light action attacks and "binding" abilities used against various enemies.
Adult-Oriented Content: The game is classified as an 18+ eroge (adult game). It features "game over" scenes and specific interactions involving slime and other hazards typical of the "monster girl" subgenre.
Stage-Based Progression: The gameplay is divided into distinct stages (e.g., Stage 1, Stage 2) featuring platforming challenges and boss encounters. Found family – Hasumi bonds with the Sisters,
Magical Girl Aesthetic: The protagonist Hasumi is designed as a "magical girl" character.
If you are looking for a specific new feature to add for a mod or a hypothetical sequel, consider:
Deep Sea Exploration: Expanding beyond the jungle into fully underwater levels with specific swimming mechanics.
Sister Synergy: A tag-team mechanic where you can switch between Hasumi and the "Deep Sea Sisters" to solve puzzles. Mission Mermaiden ~Hasumi and the Deep Sea Sisters - RAWG
Imagine Studio Ghibli meets Arkane’s Dishonored:
The title hints at the boss structure. The "Deep Sea Sisters" likely function as the primary antagonists. In games of this genre, these fights are usually the pacing milestones. Each sister likely commands a different sector of the map and offers a unique combat challenge, forcing the player to master specific mechanics.
