Gaming Guide

Harpoon a Fish Roblox Full Guide: How the Dive, Feed and Sink Loop Works

Harpooning, aquarium earnings, fish evolution, the fat meter and early crates in FirstTry's deep-sea Roblox simulator.

Harpooning, aquarium earnings, fish evolution, the fat meter and early crates in FirstTry’s deep-sea Roblox simulator.

Image: FirstTry

Harpoon a Fish is a Roblox simulator from FirstTry where getting fatter is the main way to progress. You spear fish underwater, carry them back to an island aquarium where they earn money, and eat until your character is heavy enough to sink into deeper zones. Those zones hold rarer catches and sea monsters. The game runs six-player servers, lists more than 1,800 fish in its index, and lets players steal catches from each other. You can launch it from its official Roblox page.

Quick answer: Dive, harpoon fish, and surface when the bag is full. Place catches in your aquarium to earn $/s, feed spares to evolve them, then fill the fat meter to 100/100 to sink deeper.


Harpoon a Fish core loop on Roblox

The game’s systems form a cycle: one stage supplies the next, and cash, body weight, and catches accumulate together.

StageWhat happensWhat it produces
DiveDIVE button at the shorelineAccess to the water
HarpoonAim, fire, hit the timing markFish in your bag
SurfaceSpace when the bag is fullCatches back on the island
AquariumPlace and name fishMoney per second ($/s)
Feed and evolveSpare fish go to displayed fishDouble $/s per evolution
EatMukbang Table fills the fat meterDeeper zones

Harpooning: the timing wheel and bag limits

Catching is not a click-and-collect action. When you fire at a fish, a circular timing meter appears with a spinning indicator. You have to click while the indicator is over the marked sweet spot to land the catch. The game’s own pitch describes it as timing your reels. Each result card shows the species, its rarity tier and its weight. Weights vary a lot, even among early fish.

Harpooning First Fish00:19Harpooning First Fish
A landed catch shows rarity and weight. This Uncommon Swordfish came in at 3,943kg on the first dive. Shown at 00:19 in VendoPlus’s video. Image: FirstTry

Your bag limits how long a dive lasts. A fresh account holds two fish. When the bag fills, the game shows “BAG FULL! GO FEED YOUR FISH!” and “PRESS SPACE TO RETURN,” and pressing Space takes you back to the island. The total weight you’re carrying shows on screen as you surface.

Returning to Surface00:24Returning to Surface
A starting bag holds two fish. Here it is full at 2/2, with 4,064kg on the way to the aquarium. Shown at 00:24 in VendoPlus’s video. Image: FirstTry

Fish don’t respawn constantly. A “NEXT FISH SPAWN IN” timer counts down to the next wave. Server-wide announcements also flag rare spawns in specific zones as they happen.


Aquarium income, feeding and evolution

Back on the island, caught fish go into your aquarium. When you place a fish, the game asks you to name it. You can type a name, pick “RANDOM NAME,” or choose “NO NAME.” Placed fish become pets that earn money every second, and that income pays for most of what comes next.

Fish you don’t display still have a use. The feed menu lets you give spare catches to a fish in the aquarium. Once a displayed fish has eaten enough, it can be evolved. The game says plainly that “evolving fish DOUBLES their $/s.” In the tutorial, a Swordfish named LittleTim eats a Rainbow Trout and evolves right away.

Feeding & Evolving Fish00:37Feeding & Evolving Fish
The feed menu turns a spare Rainbow Trout into growth for LittleTim, which moves the fish toward an evolution that doubles its income. Shown at 00:37 in VendoPlus’s video. Image: FirstTry

The aquarium starts small. The first upgrade adds two slots, which means more fish earning at the same time.


Fat, the Mukbang Table and deeper zones

Depth in Harpoon a Fish depends on your body weight, not on gear. Your character has a fat meter, and the prompt “Get FAT to SINK DEEPER!” starts at 0/100. You fill it at the Mukbang Table. The tutorial lets you buy the table for $0. Once you sit down, your character eats food one item after another, and the meter rises quickly. Reaching 100/100 lets you sink past the starting waters.

Buying & Using Mukbang Table00:54Buying & Using Mukbang Table
Eating at the Mukbang Table fills the fat meter. At 24/100, this character is about a quarter of the way to sinking deeper. Shown at 00:54 in VendoPlus’s video. Image: FirstTry

Deeper water has its own named zones, and server announcements show what lives in them. Shipwreck is the first deeper area most players reach. Even its common catches there are heavier and stranger than fish near the surface, including a radioactive variant.

ZoneAnnounced spawnRarity
ShipwreckMosasaurusLEGENDARY
LavaDemon PliosaurEXOTIC
VoidRiftmaw ManateeLEGENDARY

The game warns that danger grows the deeper you go. Its Roblox page also lists a “NEW ZONE??” event for Wednesday, October 21, which teases something below the Void. No details about that zone have been confirmed yet.


Fish weights from the first two dives

Rarity and weight don’t always line up. A Common Octopus from Shipwreck outweighs the Uncommon Swordfish caught in the starting waters.

FishRarityWeightWhere
Rainbow TroutCOMMON121kgStarting waters
SwordfishUNCOMMON3,943kgStarting waters
Shadow PrawnCOMMON37kgShipwreck
OctopusCOMMON6,115kgShipwreck
StripesCOMMON1,202kgShipwreck
Radioactive Amber ChubCOMMON679kgShipwreck

Tutorial reward, Free Gifts and the Bonzo objective

The tutorial ends after your first trip to the Mukbang Table. Finishing it permanently adds +3 Bag Size, so the next dive holds five fish instead of two. A new objective, “Talk to Bonzo,” then appears in the corner of the screen.

Tutorial Completion01:06Tutorial Completion
Finishing the tutorial grants +3 bag size and starts the next objective, a conversation with Bonzo. Shown at 01:06 in VendoPlus’s video. Image: FirstTry

Bag size can also be raised for a short time. The Free Gifts menu hands out timed perks. The first one is +10 BAG for three minutes, which makes a single dive much longer.

Index & Free Gifts01:24Index & Free Gifts
The first Free Gift is a temporary +10 bag boost that lasts three minutes. Shown at 01:24 in VendoPlus’s video. Image: FirstTry

Crates, keys and harpoon drills

Harpoons come from crates. Each crate opens with a matching key or with Robux. Keys come from the shop’s free reward, which gives Wood Keys +5 and Gold Key +1, from starter packs, and from codes.

CrateKey costRobux cost
Wood Crate5 Wood Keys3 Robux
Stone Crate1 Stone Key9 Robux
Gold Crate1 Gold Key24 Robux
Ruby Crate1 Ruby Key79 Robux

A Wood Crate gives harpoon weapons such as drills and bats. Some have passive effects. The Red Drill, for example, adds +1% Mutation Chance, which raises the odds of catching mutated variants like the Radioactive Amber Chub.

The game’s Roblox page promotes the code MONSTER, which gives +3k XP and +3 Ruby Keys. You enter it in the code box inside the in-game Settings menu, and the rewards are added to your account right away.

The paid shop includes these starter offers:

  • Bone Starter Pack (39 Robux): $5K/s, a Legendary harpoon and +10,000 XP
  • Greenland Hydra (9 Robux): +33% money
  • Key Starter Pack 1 (9 Robux): +5,000 XP, five Stone Keys and five Wood Keys

Stealing fish from other players

Harpoon a Fish isn’t a solo game. With up to six players per server, you can aim your harpoon at a fish another player is reeling in and try to take it. Only one player ends up with the catch. That means a rare spawn announced across the server can draw several harpoons at once, and your own catch can be contested the same way.

For long-term goals, the fish index tracks the 1,800+ species and shows which ones you still need. The aquarium is where your best catches are displayed and evolved. Most of the game’s progression comes from repeating the same cycle: dive, catch, feed, eat and sink, with each pass reaching heavier and stranger fish.