A strategy game that runs on a phone with no install

The constraint

The rule was that it had to run in a mobile browser, from a link, with no download and no install, on a mid-range phone, not a flagship. That removes most of the shortcuts available to game development and forces every decision through a performance budget.

What that teaches about ordinary websites

A game has to produce a new frame roughly every sixteen milliseconds or a person can feel it. Nothing on a normal website is that demanding, which is precisely why it is a useful discipline. Once you have had to account for every millisecond, the habits stay.

The techniques transfer directly: keep the work per frame small and predictable, never make the main thread wait on something it does not need, avoid layouts that force the browser to recalculate everything, and treat every added asset as a cost that has to justify itself.

The numbers we hold ourselves to

Because performance claims are easy to make and rarely checked, here is what we actually measure and where our own pages sit.

Google reports two field metrics that matter commercially. Largest Contentful Paint is how long until the main content appears, the target is under 2.5 seconds. Cumulative Layout Shift measures how much the page jumps around while loading, the target is under 0.1, and it is the one that makes people tap the wrong thing.

Every page on this site is measured against both automatically before it can be published. At the time of writing the worst page on the site measures a Largest Contentful Paint in the low hundreds of milliseconds and a layout shift of effectively zero. Those are lab numbers on a fast connection rather than field data from real visitors, and we would rather say so than quote them as if they were the same thing.

What actually makes a browser feel slow

The common assumption is that slowness comes from too much content. Usually it does not, it comes from a small number of specific mistakes, and they are the same on a game and on a plumber’s website.

Images shipped far larger than the space they are displayed in are the single most common. Fonts that block the page from rendering until they arrive are second. Third-party scripts, chat widgets, trackers, embedded videos, cookie banners, are third, and are the ones nobody audits, because each was added by a different person for a good reason and no one ever removed any.

The fourth is layout that shifts as things load: text appears, then an image arrives above it and pushes everything down. It reads as cheapness even to people who could not name what happened, and it is why we reserve space for images before they load rather than after.

Why it is on this list

Not because most businesses want a game. Because a site that scores well on speed is usually a site built by someone who has had to care about it under pressure. The Core Web Vitals numbers we hold our own pages to come from the same place as this.

Related case studies