Construct a thriving aquarium by collecting diverse fish species while managing tank upkeep and earning currency for upgrades and decorations. The game combines light management tasks like feeding and cleaning with idle progression mechanics, letting you expand your collection passively. Best suited for players seeking a low-stress, meditative experience rather than challenging gameplay.
About this game
Build and manage your own aquarium by collecting fish, earning money, and unlocking decorations. Feed your fish, clean the tank, and enjoy relaxing idle progression in this cozy 2D aquarium simulation.
Players, last 32 days
Peak 3 · Low 0
Daily peak concurrent players, sampled once a night from Steam.
What players are saying
▲ Recommended10 hrs
ARC Aquarium delivers a peaceful idle simulation that revolves around creating and nurturing a thriving virtual aquarium. Instead of emphasizing fast-paced gameplay or demanding management systems, it focuses on slow, rewarding progression that allows players to enjoy building a colorful underwater habitat at their own pace. The game's straightforward design makes it approachable for newcomers while still offering enough long-term goals to keep fans of idle games engaged. Every session feels calm and inviting, making it an ideal title for players looking to unwind rather than chase high-pressure objectives.
The game's strongest feature is its steadily expanding collection of aquatic life. Players can unlock dozens of different fish species, each with its own appearance, growth cycle, and contribution to the aquarium's economy. Feeding fish helps them gain experience and mature, creating a satisfying sense of progression as the once modest tank gradually transforms into a lively aquatic showcase. Watching the fish swim naturally throughout the environment adds personality to the aquarium, while the idle mechanics ensure that progress continues even when the game is closed. This balance between active participation and passive advancement makes returning to the game consistently rewarding without ever feeling like a chore.
Customization is another major highlight, allowing players to shape the aquarium according to their own preferences. A wide variety of decorative items and multiple background themes provide numerous opportunities to create unique underwater displays. Decorations can be repositioned, resized, or replaced whenever inspiration strikes, encouraging experimentation instead of locking players into permanent decisions. The freedom to redesign the aquarium over time helps maintain long-term interest, as players can continually refresh the appearance of their aquatic world while unlocking additional decorative options through progression.
The gameplay loop remains intentionally simple yet effective. Fish generate income that can be reinvested into purchasing new species, expanding the aquarium, or acquiring decorative upgrades. Regular maintenance tasks such as feeding fish and cleaning the tank introduce just enough interaction to keep players involved without disrupting the game's relaxing pace. Dirt accumulation encourages occasional check-ins, while cleaning rewards additional experience instead of feeling like a punishment. This design philosophy reinforces the title's casual nature, making every interaction feel meaningful while avoiding the frustration often associated with more demanding simulation games.
Visually, ARC Aquarium succeeds through its bright art direction and pleasant animations rather than technical complexity. Fish move smoothly through the water, decorative objects help create depth, and subtle visual effects make the aquarium feel alive. Combined with its soothing soundtrack, the presentation creates an atmosphere that complements the idle gameplay exceptionally well. The game's modest system requirements also make it accessible to a broad audience, ensuring that players can leave it running in the background without placing significant demands on their hardware.
Although the experience may lack the complexity and strategic depth found in larger aquarium management simulators, its simplicity is also one of its greatest strengths. The game never overwhelms players with unnecessary systems, instead choosing to provide a comfortable and relaxing progression loop built around collecting fish, decorating aquariums, and gradually expanding a thriving underwater environment. Players seeking intense management challenges may find it too light, but anyone looking for a cozy idle experience with satisfying customization and consistent progression will likely find plenty to enjoy. ARC Aquarium understands its audience well and delivers a charming simulation that remains enjoyable through its relaxing pace and welcoming design.
{STEAM_CLAN_IMAGE}/45943665/44d4a99d55232f16d19ac9b522fa3fdb25141184.jpg This update is all about how the fish move. Schooling Fish of the same species now swim together. Each school follows a leader and holds its formation instead of drifting apart, so a tank full of neons reads as one shoal rather than twenty separate fish. Formations spread out in depth as well as side to side, so a large school fills the tank naturally instead of stacking into a single flat band. Bodies that stay level Fish no longer tip their heads up or down when they swim vertically. Bodies stay parallel to the floor at all times. The old tilt made a fish rising to the surface look like it was standing on its tail. New squash-and-stretch motion replaces it. Bodies compress and extend in time with the tail beat, so you can still read the burst-and-glide rhythm at a glance — just without the nose in the air. Pacing Cruising speed now drifts gently up and down instead of holding one flat value, which makes the tank feel alive rather than mechanical. The variation is deliberately subtle — wide enough to notice, narrow enough that nothing looks like it is stuttering. Swimming boundaries, feeding, breeding and every other tank behaviour are unchanged. The demo receives the same update.
Fixed Gold no longer breaks past 2.1 billion. Any balance above 2,147,483,647 wrapped around into a negative number, and restarting the game reset it to zero. Gold is now stored as a 64-bit value, so that ceiling is gone. If your save already went negative, it is repaired automatically the next time you load — you get the exact amount back, not a rounded guess. Selling a full collection stack paid far too little. A stack's total was capped at 2.14 billion gold, so most of its value quietly disappeared. You are now paid the full amount. New 36 new late-game decorations — 161 in total. Sunken cabins and temple ruins, a shipwreck with treasure and cannons, a sphinx and a fallen obelisk, lava rock and amethyst, torii gates and pagodas, and a few oddities: a mushroom house, a yellow submarine, a red telephone box. They unlock from level 126 to level 161. Cure All. A button appears whenever fish in your tank are sick and cures every one of them in a single click for the total cost. Fish now swim behind your decorations as well as in front of them, so the tank finally has depth. Changed Curing a fish now costs 10% of that fish's value instead of a flat 1 gold. Every new line of text is translated into all 23 supported languages.
Localization update The 125 collection fish added in the last update had their descriptions written only in English. Now every one of them is described in all 23 supported languages, the same as the original 125 species. 2,875 fish descriptions, covering the full catalogue of 250 species. Nothing else changed — no balance, no prices, no save data. If you play in anything other than English, open any collection fish and you will see its description in your own language.
Posts come from Steam's official announcements feed.