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Watch trailer on Steam ↗Helle's Undersea City Project - Bringing Air to The Garden
Caro Builders · Published by Emma Create · Official site ↗
Very Positive — 82% positive (84 reviews) · 23 achievements
Last updated 27 Sept 2026
Helle's Undersea City Project - Bringing Air to The Garden - Grow and expand the land with air, aiming to rebuild the undersea city with a lone girl, Hele! A new type of undersea city-building simulation game!
£11.77
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Price history
Adventure, Indie, Simulation · 2023 · More £5 - £15 games
Explore Helle's Undersea City Project - Bringing Air to The Garden, where you'll grow land with air and expand the submerged metropolis in this 2023 indie sim.
About this game
Build your own undersea city with Hele!
Hele's Undersea City Project" is finally here!
Note: The Steam page is machine-translated, but the games are all natively translated!
◇What kind of game is "Hele's Undersea City Project"? ◇
This game is a simulation game that takes place on a wide ocean floor, where "land" is cultivated and "cities" are built!This is an undersea city-building simulation game set in an undersea city that has lost its people, where you and the main character "Hele Tokitsumi" aim to restore the city.
<The goal is to expand the city by utilizing air-generating structures called "Mira's Flowers" and cultivating the surrounding land,
The goal is to restore the original vitality of the city.
The estimated playing time to complete the game is 10 to 12 hours.
About "air" and "land development"
Buildings consume "air" to operate,
Air must be produced and supplied by a plant called "Mira's Flower."
.In order to plant "Mira's Flowers," the land grade must be raised to grade 2,
In order to plant "Mira's Flowers," the land must be cultivated.
In order to raise the land grade, it is necessary to acquire a "prosperity value".
The "fertility value" can be obtained at random from the land around the facility when the residents use the facility,
When a certain amount of "thriving value" is acquired, the land grade will be raised.
About Buildings
.Each of the more than 50 buildings in this title is classified into four types.
.Dwellings, which allow residents to call a town home,
Production facilities," which can be set up around special terrain where resources are buried, and where residents can obtain resources when they visit,
Processing facilities," which can earn money in exchange for resources,
Commercial facilities," which residents can use to earn money,
Within the same category, there are many buildings that have their own characteristics.
It is important to note that these facilities will not function without a supply of "air" and a connection to the road.
- "Mira's Flowers"
.The "Mira's Flower" that supplies air to the undersea city has two other factors in addition to the "supply mass range" and the "supply amount to the mass".
The "Air Cylinder Accumulation" indicates the amount of air that can be plucked apart from the supply as a resource.
There are several types of Mira flowers, each with different characteristics, so the key to the strategy is to develop the city while utilizing various Mira flowers according to the environment and progress.
-About the exploration function
.Exploration is required to obtain recipes for new buildings, Mira's flower seeds, mysterious oparts needed to liberate the story, and area liberation items.
The objective is to board an exploration boat and wade through enemies and traps that lurk in the deep sea to obtain the items and to step over them.
There are three parameters for exploration boats: HP, air, and payload, each of which can be strengthened with money.
In addition, items that aid in exploration can also be purchased with money,
These elements will be used to advance the strategy and city development.
.About research
.Items obtained through exploration can be used by researching them.In addition to items, special research such as "area release" and "tourist events" can be performed when certain conditions are met, so actively conducting research and releasing new functions and buildings is a key to further enjoying the game.
.◇There are 3 points to enjoy the game even more!
Cute dots! Residents with rich personalities!
In this title, including the main character Helle,
More than 30 different characters will enliven your town with their dot-pictures.
Some of the inhabitants are cute animals...?
Please look for them!
You and Hele will weave a story that is well worth reading!

The setting is the underwater city of Garden, where the sky is covered by the sea.
In this city built by the ancient people who escaped from the fire-engulfed earth long ago, the "Mira Flower," which produces air, sustains the lives of the residents,
The "Mira Flower," which produces air, supports the lives of the inhabitants.
The disappearance of Yona Kujira, the person in charge of governing and managing the Garden, has left the city in ruins,
The "Sengu," a Shinto ritual in which the city is rebuilt from the ground up once every 150 years.
The effects of these events caused many residents who had been living peacefully in the Garden to flee to other underwater cities.
The only one in the undersea city that has lost everything, buildings and residents,
Hele Tokitsumi" is struggling to bring the city back to life.
In the midst of all this, the player, transformed into a stuffed sheep, is sent to the Garden by chance,
The player, disguised as a "stuffed sheep," is sent to the Garden by chance.
Together with Herre, you and Tokitsumi will work together to make the Garden a great town again!
Over 50 different types of buildings and 3 difficulty levels to choose from for a variety of fun!
Don't destroy the world view,
In order not to destroy the world view, we have prepared more than 50 types of original architectural designs!
In addition, there are three difficulty levels in this game: [EASY], [NORMAL], and [HARD]!
There is also an EASY mode for those who are new to city planning games, and a NORMAL mode for those who have played many city planning SLGs,
The game also offers three difficulty levels: EASY, NORMAL, and HARD!
Together with Hele,
Let's start building your own town with Hele!
We welcome video distribution and submission of this work via video submission websites.
If you have any questions, please contact us by DM on our X account.
System Requirements
Will my PC run this? →Minimum
- OS *: Windows 7 / 8 / 10 / 11
- Processor: Intel Core i5
- Memory: 4 GB RAM
- Storage: 500 MB available space
Recommended
- OS: Windows 10 / 11
- Processor: Intel Core i7
- Memory: 8 GB RAM
- Storage: 500 MB available space
Supported Languages
Latest news
AnnouncementsOfficial
GW Limited-Time Offer: Emma Create 4-Game Bundle is 25% Off!
To everyone who has added our games to your wishlist: For a limited time during Golden Week, we’re holding a special bundle sale featuring four Emma Create games!This bundle includes four different games, including management simulation, city-building SLG, maritime trading, and Nextuber raising simulation — all available for 25% off. It’s a great chance to enjoy the bundle at a price that’s almost like getting one game for free.If you’ve been interested in our games but haven’t had the chance to play them yet, now is a perfect time to check them out!👇Bundle page Sale Period: 4/29 – 5/6Read full article on Community Announcements (エマ)AnnouncementsOfficial
"Heroic Songs: the Remix!" × "Helle's Undersea City Project" Bundle Sale!
A special bundle is coming, featuring Frontier Works’ latest release *Heroic Songs: the Remix!* together with Ema Create’s popular title *Helle's Undersea City Project - Bringing Air to The Garden*!*Heroic Songs: the Remix!* is a city-building simulation game where you travel through four different worlds to create the “sacred place” of idols. While nurturing the main heroine *Akari Sunohara* as an idol, you’ll also develop the mysterious land known as the “space between worlds”! With idols joining in city-building, the cuteness is overflowing!The charm of *Helle's Undersea City Project - Bringing Air to The Garden*, beloved by many fans, is also inherited in *Heroic Songs: the Remix!*, and comparing both titles side by side will surely double the fun!Don’t miss this chance to enjoy the appeal of both a brand-new title and a fan favorite at once! Be sure to check them out together!Read full article on Community Announcements (エマ)Patch NotesOfficial
Helle's Underwater City Project ver1.3.0 has been released.
- Supported Chinese (Traditional).Read full article on Community Announcements (isekai.gamedep)Patch NotesOfficial
Notification of ver1.2.0 update
We are pleased to inform you about the contents of the update implemented on November 30. - Support for implementation of the Nagino Mashiro Resettlement DLC As it will appear as DLC, it will no longer appear as a tourist. Updates Update and correction of the staff roll Thank you for your continued support.Read full article on Community Announcements (テチチ)AnnouncementsOfficial
Free DLC is now available!
Vtuber『凪乃ましろ』とのコラボ企画を盛り上げてくださった御礼と感謝として、凪乃ましろの専用住居と住民化DLCを配信しました! ●Addition of a special residence with a "Mashiro Nagino" motif! This DLC adds research for a special "Mashiro Nagino"-motif residence that can be built only once in the game. Please acquire the building from the research and welcome "Mashiro Nagino" to your garden! ●Mashiro Nagino" is moving to the Garden! Mashiro Nagino" will appear as a new character from a tourist to a resident! Mashiro Nagino," who appeared as a "tourist" in the first version, will appear as a resident character in this DLC. As a resident character, you can have her appear anywhere and anytime you like!Read full article on Community Announcements (テチチ)






