Trimps

Trimps starts with a single creature and a breeding screen, and ends with an army of genetically engineered soldiers fighting through hundreds of zones. Somewhere in between, you will reset the entire game for permanent helium-based perks, discover heirloom equipment, and start optimising damage-per-second per geneticist with a spreadsheet. It is that kind of idle. BrownProbe released it on the web in 2015 and brought it to Steam in May 2022 as a free title, and the community cites it alongside Cookie Clicker and Realm Grinder as a genre pillar.

What the loop feels like

Trimps breed automatically, filling your army for combat, and the soldiers fight through zones in real time while you tend the machinery behind them. Every zone drops resources that feed back into breeding and upgrades, and the frontier keeps moving. That's Trimps.

Then the Portal opens. Pushing to new zones earns Helium, activating the Portal resets the run, and the Helium buys permanent perks that make every subsequent run faster and deeper until the reset itself is the game. That's Trimps, six months in, when the spreadsheet comes out.

How it actually works

The breeding-and-combat loop is the floor: army growth is automatic, zones chain into each other, and formations trade attack for defence so the right setup matters as much as raw numbers. The prestige layer is the spine: Helium, earned by zone progress, becomes permanent perks through a tree deep enough that the community built the Perky calculator because perk optimisation is a genuine maths problem. Heirlooms add the second meta-progression layer: equippable Shields and Staffs rolled and rerolled with Nullifium as the reroll currency, so gear farming sits alongside zone pushing as a long-term project. The automation layer grows until the game largely plays itself between decisions, which is the idle genre's real promise delivered properly: the game runs for months without running out of things to optimise, and the Fandom wiki documenting it all is genuinely deep.

Where it stumbles

The spreadsheet reputation is a feature and a filter. The systems interlock so heavily that new players face a wall of tabs, and the community's own tools exist because the game does not explain its optimisation space itself; a wiki dependency is a real cost for a game this deep. The presentation is functional rather than flashy, and the early hours are slower than the genre's modern standards before the automation catches up. And the sheer length is honest about its price: this is a months-long commitment by design, and players who want a completable arc in an evening should look elsewhere. None of this is accidental, and none of it is hidden; the game has been open about being a long-haul machine since 2015.

Playing it today

Free on Steam, the definitive version with cloud saves and better performance, and free in the browser if you want to sample the loop first. For the other pillars it gets cited beside, Cookie Clicker and Realm Grinder are both in the catalog.

The verdict

The spreadsheet idle that earned the nickname as a compliment: deep, free, endlessly optimisable, and one of the few games in the genre that outlasts the spreadsheet it asks you to build.