Fish Idle 2: Underwater Mystery

An idle game that isn't, according to its own players

Fish Idle 2: Underwater Mystery pitches itself as "a unique idle fishing arcade featuring smooth graphics and intuitive mechanics" — steer a boat, let fish bite automatically, and build up a "Fish Kingdom" through upgrades. On paper that's a clean fit for this library's core genre. Steam's own community, though, votes with its tags rather than the marketing copy: "Idler" sits 18th on the vote-weighted tag list with 39 votes, well behind "Casual" (197), "Adventure" (186), "Point & Click" (147), "Arcade" (145) and even "Trading" (53). Reviewers make the same point in plain English. "I have no idea why it is called idle," one writes; another opens a review by noting "there are no idle mechanics and 0 offline pay." The disconnect between the store page's genre framing and what the people actually playing it call the game is the first sign that this review needs to look past the trailer.

What the screenshots actually sell

The most useful research move for any idle game is to look directly at what the developer chose to show, rather than what the "About This Game" text says — and here it's decisive. Of the six official Steam screenshots, one is a dedicated tutorial slide with no ambiguity at all. It reads, in three steps: "Complete Special Quests To Gain Chests!", "Open Chests To Collect Strong Items", and "Trade Them On Steam Market" — illustrated with a "Harpoon" weapon card priced at "323.4$" sitting next to a green SELL button. This is not a player's screenshot or a review's allegation; it is promotional art the developer chose to put on the store page, teaching players that the loot loop's endpoint is reselling drops for real Steam money.

The review corpus treats this as the game's defining feature, for better and worse. Chest mentions appear in 38 of the 220 English-language negative reviews read for this piece, and marketplace mentions in 11 more. The dollar figures reviewers report are not small: one 87.5-hour review describes "970 euro for chests" before noting, in a follow-up edit, that "the prices have been heavily reduced... you're paying 10 bucks for 100 chests now" after the developer responded to launch-week backlash. Another reviewer, with under an hour logged, reports seeing "over 3k euros for a stupid fishing rod." A calmer, more recent account (41 hours, posted August

2025. puts it more clinically: "every ingame loot chest and drop is saleable on the steam

marketplace, and in theory, you could work up to a modest few cents a day per account. In practice, I don't think there are enough whales on the marketplace for that." One of the game's own top positive reviews, from a 1,021-hour player, states it as plainly as anyone: "Yes it is a cash grab game... I heard the market crashed for this game in another review. I just idle it for fun and achievements." That last sentence is the honest state of the marketplace as of this review: a real-money system that launched aggressively overpriced, got walked back once, and appears to have lost most of its economic function since, according to the people still playing.

None of this requires spending a cent — the base game costs nothing, there is exactly one paid DLC (the "Welcome Pack": 500 crystals and an upgraded rod for US$4.99 / NZ$7.39), and no advertising of any kind turned up anywhere in the store material or screenshots. Several long-time players confirm in their own reviews that ignoring the marketplace entirely and just playing for achievements works fine. But a shopper who only reads the trailer would have no idea the loot system's headline use case, in the developer's own marketing, is a real-money storefront.

Chest timers and the "isn't actually idle" complaint

Beyond the marketplace, the specific mechanical complaint that recurs across the corpus is about gating, not difficulty. Screenshots show a real-time countdown reading "NEXT UNIT: 01:55:17" — just under two hours — attached to progression, and multiple reviewers describe chest and mission rewards arriving on their own delivery timers that frequently fail outright. "You'll get a 120s timer saying your chest is being delivered and when you waited it out it just goes 'delivery failed will be delivered later,'" one reports. A 1,150-hour reviewer confirms the same failure mode years into ownership: "a major progressive element (chests) is broken and will regularly not be provided to you." One of the game's own patch notes — the only patch it has ever received — specifically claims to fix "chests cooldown" and increase delivery-timer length "to reduce chance of errors," which suggests the developer was aware of the problem in November 2024 and increased the wait rather than removing the failure case.

Layered on top of the timers is a genuinely mobile-shaped control scheme: the official screenshots show a virtual joystick fixed to the bottom-left corner of the screen, the same touch-drag control convention used in mobile idle games, mapped onto mouse-and-keyboard on PC. "Clearly designed as mobile game," one reviewer summarises. "Controls are terrible on PC." Combined, the picture several detailed negatives paint is of a game whose progression loop is built around real-time waits and a touch interface first, with the PC release layered on afterward rather than designed for it.

The reskin allegation

The most serious claim in the corpus is not about monetisation directly — it's about originality. At least eight separate English-language reviews, written independently and with no obvious coordination, allege that Fish Idle 2 closely reuses assets and design from an unrelated mobile game called "Alien Invasion: RPG Idle Space." The most detailed version of the claim is worth quoting because of its specificity: "there is a sign that shows you can trade gems for eggs... Eggs aren't in this game but is in Alien Invasion. There is a moment where you can summon a special fish, when you summon this fish, it says you have summoned 'the queen of worms' — this game does not have her majesty, but Alien Invasion does." Other reviewers independently describe "near identical spawn rates of special fish as the free mobile version," "arbitrary in game cooldowns of 3+ hours," and "the same map layout." One names the publisher of the mobile game as CrazyLabs.

This review could not verify the claim directly — a Steam storesearch for "Alien Invasion: RPG Idle Space" returns no results, consistent with it being a mobile-only title outside the tools available here, and this review does not play games as a matter of policy. What can be said is that this is not a single low-vote allegation of the kind this library declines to repeat: it is a recurring, independently-corroborated pattern across multiple detailed reviews citing specific, checkable in-game details (a leftover reference to an item — eggs — that doesn't otherwise exist in this game), rather than a vague accusation. Readers weighing originality should know the claim exists and is unusually specific, without this review asserting it as settled fact.

An abandoned patch cadence

Fish Idle 2 launched on 15 November 2024. Its Steam news feed carries exactly one post, dated four days later, fixing chest-delivery timers, adding a windowed display mode, and adding several interface languages. Nothing has followed in the nearly twenty-one months since. Long-playtime reviewers confirm this from the inside: a 717-hour review states plainly, "the game is abandoned... I invested a lot of time into it, hoping it would get fixed and improve, but with no updates, there's no hope." A 2,546-hour positive review — one of the highest-playtime accounts in the sample — explains stopping after hitting max level "months ago," with "one area left" and nothing further to do. A 1,905-hour reviewer reports the same broken chest-delivery bug that the single November 2024 patch claimed to fix is still present, alongside achievements that "wont be able to be achieved because they are buggued."

The global achievement data corroborates a steep early drop-off that goes well beyond ordinary idle-genre attrition. The very first achievement — for completing the tutorial catch — sits at 25.8% globally, meaning roughly three in four owners of the game never get that far. Reaching level 4 clears the bar for only 12.5% of owners, and by level 8 that falls to 4.7%. Most crafting-tier and high-chest-count achievements sit under 1%. Some of that reflects the genre's usual long tail of very-high-value late-game unlocks, but a sub-26% completion rate on the very first achievement in the game — the tutorial catch — points at an onboarding problem more than a grind problem, and it lines up with the wave of near-zero-playtime negative reviews in the corpus (several logged under 15 minutes) describing quitting the moment the marketplace pitch appeared.

What's actually good here

It would be unfair to let the monetisation and abandonment findings crowd out the genuinely positive half of the review corpus. The top English-language positive review logs 2,375.6 hours — across six simultaneous installs, the reviewer notes — and calls it "one of my favourite games at the moment because it's simple, fun, and relaxing to play." Recent sentiment, specifically, reads better than the lifetime figure: of the 100 most recent English-language reviews (spanning 10 November 2025 to 31 July 2026), 69 are positive, against a 59.7% lifetime English rate. That gap suggests the audience installing the game today — after nearly two years of word-of-mouth about its marketplace and its abandonment — knows roughly what they're getting, and a meaningful share of them are satisfied with it anyway, chest economy and all. "I just idle it for fun and achievements," as one positive reviewer put it, is a genuinely available way to play this game, even if it is not the way the developer's own screenshots pitch it.

Final verdict

Fish Idle 2: Underwater Mystery is free, has no ads, and gives a real slice of its audience hundreds or thousands of hours of low-stress fishing. That's a defensible offer on its own. What keeps this out of a recommendation is that the developer's own promotional material sells a real-money chest-resale loop as a headline feature, that loop launched priced in the hundreds and occasionally thousands of euros before a partial walk-back, the game has received a single patch in the twenty-one months since launch while long-time players report the exact bug that patch claimed to fix still recurring, and a specific, recurring allegation from multiple independent reviewers questions whether the game's map and mechanics are its own. None of that erases the players who genuinely enjoy it — but a shopper deciding whether to install this should know the "idle fishing arcade" pitch and the game the community actually tags, plays, and argues about in its reviews are not quite the same product.