For developers

12 Incremental Game Jams Worth Entering, From Genre Jams to Big General Ones

Incremental game jam guide: the genre's twice-yearly jam, smaller idle jams and general jams that suit clickers, with dates, rules and what each is good for.

Developer guideMaintained by Maxwell PrehodaNov 1, 2026How we choose

The main incremental game jam is the Incremental Game Jam on itch.io, run twice a year by FBDW, asterisk_man and CardboardEmpress: a New Years edition starting in late December and a Summer edition in July, each with two weeks to build and two weeks to vote. Around it sit smaller genre jams, a framework jam for Profectus, and general jams whose rules happen to suit clickers.

Every jam below is linked to its real itch.io or official page, with dates, entry counts and rules as those pages showed them in November 2026. Jams come and go, so treat past dates as a pattern, and check the page before planning around it.

New Years Incremental Game Jam: best for your first incremental jam, with players who know the genre

Platform: itch.io. Free. Two weeks to build, two weeks to vote

The winter half of the genre's own jam. The 2026 edition ran from 27 December 2025 to 10 January 2026 with the theme 'Inception' and a bonus 'No Text' challenge ranked separately. It drew 25 entries and 715 ratings. The page describes IGJ as 'a bi-annual jam with a 28 day runtime.'

Entries are rated on Fun, Theme, Originality and Balance, and Balance is the one that makes this jam useful: raters are told to mark down timewalls and pacing that is too fast. That is free playtesting from people who play incrementals for fun. The 2026 results had Inceptinc by BlindsidedGames and Abiogenesis by pbrane tied for first.

Rules are short: the game must be incremental, no NSFW content, and no code, art or content prepared before the theme is announced, though public material is allowed. Questions go to the jam's Discord, linked from the page.

Watch out for: Two weeks sounds long, but raters play many games in a row. A game that takes an hour to get interesting will be judged on its first ten minutes.

Summer Incremental Game Jam: best for a second shot each year with the same community

Platform: itch.io. Free. Two weeks to build, two weeks to vote

The July half of the same series. The 2026 edition ran 4 to 18 July 2026 with the theme 'Parallel Universes,' 28 entries and 470 ratings, rated on Fun, Theme fit, Uniqueness and Balance. Earlier summers used themes like 'Evasion' in 2024, when 26 entries drew 872 ratings.

The 2026 results were led by MORE ME by Milo, Could Be Me! by TheyCallMeKill and WooFooPets, and Now Time Was There by pbrane, who also tied for first in the New Years jam. Returning names are normal here, which tells you the community is small and you will get to know it.

If you missed New Years, this is the one to circle on the calendar. If you entered New Years, Summer is your chance to show how much you learned.

Watch out for: Ratings come mostly from other entrants, so rating other games is how you get yours played. Budget a few evenings for it in the voting fortnight.

Incremental Jam and Clicker Jam (Xeight): best for a one-week sprint with an optional design challenge

Platform: itch.io. Free. About one week

Xeight hosted a run of one-week genre jams: Clicker Jam Spring 2022 (34 entries, no theme, explicitly no winners), then the Incremental Jam in summer 2023, spring 2024 and winter 2024. The winter 2024 jam swapped the theme for a challenge, 'Make a game with layered elements,' and rated Overall, Innovation, Music and Sounds, Art and Effects, and Fun and Balance.

One week is the right length for an incremental's core loop plus one prestige layer. Clicker Jam's rule that games be playable at least on web or Windows is a reasonable default for any jam you enter.

We could not find an edition after winter 2024, so check Xeight's itch.io page before counting on another.

Watch out for: Series without a recent edition may be dormant. Do not plan a release around a jam that has not posted dates.

Improve My Game Jam: best for turning last month's jam game into a demo

Platform: itch.io. Free. About one week, no theme

Not an incremental jam, but the best follow-up to one. Improve My Game Jam 35, hosted by anomrac21, asked entrants to 'submit any previously developed game and improve on it somehow,' with a devlog documenting the changes.

Clock Ticker shows the path. Its itch.io page lists Clicker Jam Spring 2022 and Improve My Game Jam 35 among its jams, and the game now has a Steam page with a demo, listed as coming soon.

Use it to finish what a short jam started: fix the balance raters complained about, add the second layer you cut, write the devlog that becomes your first marketing post.

Watch out for: The devlog is required and checked. Social media links and video-only devlogs are disqualified, so write it on itch.io.

Profectus Creation Jam: best for trying a Modding Tree style framework with prizes

Platform: itch.io. Free. Ten days. Built around the Profectus engine

The Paper Pilot, who maintains the Profectus engine (a successor to The Modding Tree style of tree-based incrementals), ran the first Profectus Creation Jam from 20 to 30 May 2023 with the theme 'Break the Cycle' and cash prizes of $150, $100 and $50. It had four entries, including Delooped by ducdat0507.

A small field and real prizes make framework jams good odds for anyone willing to learn the engine. A 2025 edition ran 15 to 25 February with the theme 'Working Together!'

If you would rather start with The Modding Tree itself, our Modding Tree tutorial covers the basics either engine assumes.

Watch out for: The 2025 edition received a single entry. Tiny jams mean little feedback, so pair one with a post in the community afterwards.

One Game A Week Jam: best for unusual prompts that push an incremental somewhere new

Platform: itch.io. Free. One week, genre and prompts change weekly

Hosted by ForgeWalker Studios and jazhikho, this weekly jam rotates genres. Week 9, 6 to 13 July 2026, was 'Incremental Game' with the theme 'Haunted Garden,' the wildcard 'A resource that gets worse when stored' and the ingredient 'Ash.'

That wildcard is a better design prompt than most themes. A decaying resource fights the genre's habit of hoarding, which is exactly the kind of twist that makes an incremental memorable.

Watch the jam page for the next week that lands on incremental, or take a different genre's prompts and make an incremental anyway.

Watch out for: AI use must be disclosed under the rules, and the incremental week had seven entries. Read the rules each week, since prompts and requirements change.

Micro Jam: best for regular 48-hour practice on a fixed schedule

Platform: itch.io. Free. 48 hours, every two weeks

Micro Jam, hosted by tobias and SeeOne, is 'a bi-weekly Game Jam' with a theme and a prerequisite. Micro Jam 068, 31 October to 2 November 2026, paired 'Evolution' with 'You start with nothing!', a prompt an incremental answers almost by definition. It drew 37 submissions.

Not every round suits idle games, but the cadence is the point: pick the rounds whose theme fits, and you can ship a small incremental every month or two.

Prize eligibility requires joining the jam's Discord, and games must be in English.

Watch out for: Raters are general players, not incremental fans. Make the first minute self-explanatory, because nobody will read a wiki for a jam game.

Gamedev.js Jam: best for HTML5 incrementals chasing sponsor challenges

Platform: itch.io. Free. About two weeks each April. Browser builds only

Run by End3r of Enclave Games, the Gamedev.js Jam 2026 ran 13 to 26 April with the theme 'Machines' and 482 entries. The core rule suits browser incrementals: 'anything that can run on the Web in a browser without extra plugins,' with Unity and Godot web exports allowed.

Optional challenges add separate judging and prizes, such as Open Source (GitHub) and Build it with Phaser in 2026. An open-source incremental entered in the Open Source challenge gets seen by people who read code, which is useful feedback.

Pick it if you build in JavaScript; our JavaScript incremental tutorial gets you to a jam-ready loop.

Watch out for: With nearly 500 entries across all genres, a plain-looking incremental can get few ratings. A clear thumbnail and a one-line pitch matter more than usual.

js13kGames: best for tiny text-first incrementals and code golf

Platform: js13kgames.com. Free. One month from 13 August. 13 KB limit

js13kGames, organised by Andrzej Mazur (end3r) since 2012, limits entries to '13 kilobytes after minification and compression,' per GitHub's write-up. The theme is announced on 13 August and entrants get a month.

Incrementals fit the limit better than almost any genre. A text-and-buttons game like A Dark Room or Universal Paperclips needs no images, so the bytes go into systems and writing.

Pick it if you enjoy constraints, or want a portfolio piece that shows tight JavaScript.

Watch out for: Big-number libraries and fonts eat the budget. Stay under JavaScript's 1.8e308 ceiling, or write a minimal mantissa and exponent type yourself.

GMTK Game Jam: best for maximum exposure if your idea fits the theme

Platform: itch.io. Free. Four days each summer. Run by Game Maker's Toolkit

Mark Brown's GMTK Game Jam is the largest on this list. The official page lists over 10,500 games in 2026 for the theme 'Count Down,' up from over 6,000 in 2022, and says GMTK Game Jam 2027 starts 11 August.

An incremental that nails the theme can stand out, because few entrants make idle games. 'Count Down' is a good example: timers and decay are native to the genre.

Enter for the stretch and the audience, not for genre feedback.

Watch out for: With over ten thousand entries, most games get a handful of ratings. Without promotion of your own, expect little attention.

12 · Ours

IncrementalGames.org: best for giving a finished jam game a home after voting

Platform: Free listing. Optional paid Get featured placement from $30 a week

This is our site, so weigh it accordingly. When voting ends, a jam game's itch.io page stops getting traffic. Listing it free on IncrementalGames.org gives it a tagged profile that players can find through lists, the game finder and the new-games page, alongside the itch.io link.

If the jam game becomes a full release, you can claim the listing and update it. The optional Get featured placement puts a labelled Featured card on the home page, game pages and best-of lists for launch week.

Also post it to the other places incremental players look; our where to post guide lists them.

Watch out for: A listing is not a review. Players will judge a jam build as a game, so fix the worst bugs from the comments before you list it.

How to choose an incremental game jam

Match it to the feedback you need

If you need pacing feedback from players who know the genre, enter the New Years or Summer Incremental Game Jam, where Balance is a scored criterion. If you need a deadline more than feedback, Cookie Jam or Micro Jam will do. If you want attention from outside the genre, GMTK or Gamedev.js puts your game in front of general players.

Match it to your stack

Browser builds are the safest choice everywhere, and Gamedev.js requires them. JavaScript developers have js13kGames as a size challenge. If you want a tree-style incremental without writing a framework, The Modding Tree or Profectus gets you there, and the Profectus Creation Jam rewards using it.

Match it to what happens next

Decide before the jam whether this is practice or the start of a real game. If it is real, keep scope to one strong loop, follow up with Improve My Game Jam as Clock Ticker did, and save every rater's comment. If it is practice, pick a short jam and move on.

Join a jam page today

Open the itch.io page of the next jam you can make, press Join, and write your one-resource, three-generator plan on a sticky note. Joining is free and it puts the jam's dates in your itch.io dashboard. For the Incremental Game Jam, past New Years editions started in the last days of December, so watch the hosts' itch.io pages from early December.

After voting, list the game on IncrementalGames.org for free so it keeps finding players. If it grows into a release, the optional Get featured placement can put it in front of more players at launch.

List your game free →

Common questions

Is there a game jam just for incremental games?

Yes. The Incremental Game Jam on itch.io runs twice a year, a New Years edition starting in late December and a Summer edition in July, with two weeks to build and two weeks to vote. Smaller genre jams such as Cookie Jam (Incremental) and the Profectus Creation Jam have also run.

When is the next Incremental Game Jam?

The series is bi-annual. The 2026 New Years edition ran 27 December 2025 to 10 January 2026 and the 2026 Summer edition ran 4 to 18 July 2026. Check the hosts' itch.io pages for the next dates, since they are announced on the jam page.

Can I use Godot or Unity for an incremental game jam?

Usually, yes. The Incremental Game Jam and Cookie Jam set no engine limit, and Gamedev.js allows any engine whose export runs in a browser. A web build gets far more plays from raters than a download.

How big should an incremental game jam entry be?

Small enough to be interesting in ten minutes. One main resource, a handful of generators, one upgrade path and, if time allows, one prestige layer. Raters play many games back to back, so pacing in the first minutes matters more than total length.

Do jam games ever become full releases?

Some do. Clock Ticker was made for Clicker Jam Spring 2022, improved in Improve My Game Jam 35, and now has a Steam page with a demo. Expect to rebuild much of a jam game before release, but the feedback is a head start.