Own Game · Playable
Harbour Town
A cosy idle game I designed, playable here in the browser: catch fish, grow a fleet and set sail for a grander harbour.
4 min read
Role
Game Designer · Own project
Status
Playable · Web demo v0.1
Tools
Unity
At a glance
- Problem
- An idle game has to pay off for an active hour and a five-minute check-in alike, and its reset has to be worth taking without tempting players to take it too often.
- My contribution
- I designed the economy and progression: 14 fleet tiers, 23 improvements, the Set Sail reset and its Reputation curve, and the active-play systems, then tuned them against simulated ten-hour play.
- Where it stands
- A playable web demo, v0.1, on this page. In simulation an active player first sets sail after about 15 minutes and reaches the last tier after about 4.5 hours.
Playable
Play it in your browser
- Hold Cast net or Space to fish
- Arrow keys, Tab or a controller move between buttons
- Progress saves in this browser
- Best on a computer: the interface is designed for a wide screen.
Case study
An economy that rewards patience
How the loop fits together, the reset trap the simulator exposed, and a first tuning of merchants and tasks that made the game far too fast.
Context
Harbour Town is a small incremental game set in an evening harbour. You cast for fish, buy boats that fish for you, and eventually Set Sail to found a grander harbour, trading your progress for Reputation that makes every later run faster.
It is my own project, outside my work at Bigpoint, released under my label Pocket Harbour Games.
The loop
- Cast the net for coins. Each catch also fills a busy-harbour meter that boosts all income while it stays up.
- Spend coins on 14 fleet tiers that fish for you, and 23 improvements that multiply them.
- Set Sail: reset the harbour for Reputation. Every point earned is a permanent +15% to income, and it can also be spent in a five-upgrade Charter shop; spending never lowers the bonus, which counts all Reputation ever earned.
- Between resets, shoals, merchant ships and harbour tasks reward attention, and offline earnings make a short return worthwhile.
Intended pacing
By the first Set Sail, around 15 minutes in, a player should have seen the whole early loop: casting, the first fleet tiers, improvements, a shoal and a merchant. They should also have built enough that giving it up is noticeable, so the trade of progress for permanent Reputation is understood rather than just a button to press.
Grand Harbour, about 4.5 hours of active play, is a milestone rather than the end: the last fleet tier, with more voyages, Reputation and achievements after it.
The reset trap
Reputation grows with the fourth root of the coins earned, so doubling it takes sixteen times the coins. That stops runs collapsing into instant resets, but it also sets a trap.
At the same five catches a second, a simulated player who sails for every point they can ends ten hours with 42 Reputation and never reaches Grand Harbour. One who waits until their Reputation would double ends with 8,292, roughly 200 times more. A player who misunderstands the reset is punished hard.
My first intervention is guidance: the first-sail hint explains what a reset rebuilds, the Next Voyage card shows the doubling target, and the confirmation dialog warns when the gain is small. Sailing early stays possible.
Why guidance rather than a different economy? The curve is intentional: it keeps later runs meaningful, and sailing for every point isn't meant to be a viable way to play, so I would rather teach when to sail than flatten it. Guidance was also the cheapest, most reversible first step, and I want playtest evidence before changing the core curve.
It is not validated yet. The simulator follows fixed rules, so it can't show whether players read the guidance or act on it. That needs playtesting.
Tuning merchants and tasks
The first version of merchant ships and harbour tasks cut the first Set Sail to 2.5 minutes and Grand Harbour to an hour. Task rewards counted towards the coin goals, and Buy max made fleet goals instant.
Tasks are now active-play goals (fish, casts, shoals, a trade) paying 30 seconds of income, and a cargo deal nets about a minute. Together they bring an attentive player's first sail about 13% sooner and Grand Harbour about 18% sooner.
Economy Breakdown
The numbers behind the harbour
The fleet's cost ladder from the game's data, and how six simulated players fare over ten hours.
Simulated with a bot playing the real economy by fixed rules: how the economy behaves, not how people play it.
Base payback increases sharply in the later tiers
Base payback (cost divided by output) stays within a few minutes for the first four tiers, then climbs to about three weeks for Grand Harbour. Improvements, achievements and Reputation close that gap, which is what makes a reset worth taking.
| Tier | Base payback, log scale | Cost | Payback |
|---|---|---|---|
| 1Dock Fisher | 15 | 3 min | |
| 2Rowboat | 100 | 2 min | |
| 3Fishing Trawler | 1.1K | 2 min | |
| 4Fish Market | 12K | 4 min | |
| 5Cargo Ship | 130K | 8 min | |
| 6Shipyard | 1.4M | 17 min | |
| 7Trading Company | 20M | 43 min | |
| 8Ocean Liner | 330M | 2.1 h | |
| 9Canal Company | 5.1B | 5.4 h | |
| 10Harbour Bank | 75B | 13.0 h | |
| 11Seaside Resort | 2T | 1.4 days | |
| 12Clipper Fleet | 60T | 3.3 days | |
| 13Port Authority | 2Qa | 8.6 days | |
| 14Grand Harbour | 70Qa | 20.8 days |
Coins: K thousand, M million, B billion, T trillion, Qa quadrillion.
Waiting to sail beats sailing often
Reputation after ten simulated hours. The eager player catches as fast as the active one, but sails for every point and ends with 42 Reputation against 8,292.
| Profile | First sail | Grand Harbour | Reputation at 10 h, log scale | Reputation |
|---|---|---|---|---|
| Continuous activeHolds Cast net (5/s), sails when Reputation would double | 15 min | 4 h 30 min | 8,292 | |
| Continuous moderate2 catches/s, otherwise the same | 20 min | 6 h 26 min | 4,096 | |
| Eager activeHolds Cast net (5/s), sails for every point | 15 min | Not reached | 42 | |
| Low-input continuousA tap every 2 s (0.5/s), ignores shoals, merchants and tasks | 43 min | Not reached | 32 | |
| Five minutes an hourHolds Cast net while present, offline earnings between | 2 h | Not reached | 6 | |
| Five minutes every 4 hHolds Cast net while present, offline earnings between | 8 h | Not reached | 2 |
Holding Cast net or Space repeats at up to 5 catches a second, so the 5/s profiles hold the button rather than tap. The two check-in profiles, with offline earnings between sessions, are the closest to idle play.
Design decisions
- 14 fleet tiers, from Dock Fisher to Grand Harbour. Each base cost is 7 to 35 times the one before, and the steps widen in the late game.
- 23 improvements that double a tier, double the whole harbour, or add a share of income to every catch.
- Reputation on a fourth-root curve, at +15% income for every point ever earned, so a reset is a choice about timing rather than a reflex.
- Guidance towards sailing when Reputation would double, in the first-sail hint, the Next Voyage card and the confirmation dialog. Not yet validated with players.
- Active play rewarded through the busy-harbour meter, shoals, merchants and tasks; offline earnings keep a short check-in worthwhile.
- Each change checked against six simulated ten-hour profiles, from continuous active play to five minutes every four hours.
Outcome
Playable on this page as web demo v0.1. In simulation, the first Set Sail comes after about 15 minutes holding the cast button, 20 at two catches a second and 43 with a tap every two seconds, and active runs settle at 20 to 70 minutes between sails.
Limitations
Every figure here comes from a balance simulator: a bot playing the game's real economy by fixed rules. It shows how the economy behaves, not how people play it.
The bot takes every deal and claims every task the moment it can, so the effect of merchants and tasks is an upper bound.
The guidance against sailing too early is untested with players.
What I'd look at next
- When real players choose to sail, and whether the guidance towards doubling changes it.
- Whether 15 minutes is long enough for the early loop to land before the first reset.
- Whether players who only check in occasionally, and don't reach Grand Harbour within ten hours, keep coming back.