A 2020 phone game rebuilt for the browser, with a global leaderboard

The game. Five kinds of fruit fall (banana, orange, pear, strawberry, watermelon) and six animals (chicken, cow, dog, elephant, penguin, pig). Catching fruit scores, and four catches in a row without a hit start a multiplier that climbs to five times; a hit resets it and costs a heart, of which there are seven. The fall speed and your own speed both rise with the score, so a round starts gentle and ends frantic. Every catch plays one of thirteen little voice clips — the "yum" and "no!" noises are in a handful of languages, Danish, Polish, German and Thai among them — over a single jazzy loop, with a screen shake and a particle burst on impact.

A modern engine underneath the same game. The hand-rolled render loop is gone. The game is now an ordinary Flame game where the views are router pages, and the hearts, score, combo, buttons and leaderboard panel are all self-positioning components. Just as important, the rules that used to be tangled into the loop are now plain functions with no graphics attached — difficulty curve, board geometry, and the collision check that decides whether you caught something. That last one is a swept test rather than a snapshot, so a fast-falling fruit cannot teleport straight through the player between two frames. Thirty-four automated tests cover those rules, plus a golden image of the home screen.

Making it behave in a browser. Two things were learned the hard way and are now written into the code as warnings. The game only renders reliably as a bare game widget — every attempt to wrap it in a layout widget blanked the screen — so the letterboxing is done inside the game instead: one centred nine-tile play column that the background, the HUD, the buttons and every spawn anchor to, at any window size. And the graphics runtime was being served uncached, which meant roughly 28 KB/s to a distant player: a caching rule at the edge took that to around 60 MB/s worldwide, which is the difference between "black screen, must be broken" and "it just opens".

A small API of its own. Global scores run on a FastAPI service with a SQLite file behind it, on the same server, proxied at vpg-api.grn.dk. There are no accounts and no email addresses: identity is an anonymous id minted in the browser on first play, with an optional nickname that goes through a profanity filter, and a transfer code if you want to carry your profile to another device. Because a public score endpoint is an invitation, submissions are signed, timestamped, rate-limited per device and per address, and capped at a score no honest round can reach. (One detail worth remembering: the free certificate at the edge covers only a single subdomain level, so api.veganpower.grn.dk could never work and the API lives at vpg-api.grn.dk instead.)

Fruit Rumble, the multiplayer beta. Two to four players join a four-letter room code for a ninety-second round in a shared arena, where bumping into someone shoves them — steal the fruit they were lining up, or push them into a cow. The server owns the simulation and runs it twenty times a second, because otherwise two players will never agree about who shoved whom; clients send only their input. Your own character is predicted locally and reconciled against the server's acknowledgement, the rest of the world is interpolated through a buffer that sizes itself from the jitter it actually measures, and an on-screen NET readout shows the round-trip time, the jitter and the current buffer so the feel can be argued about with numbers instead of adjectives.

Shipping it, every push. A build runs within ten minutes of a commit and refuses to go out if anything is red: the analyzer, the thirty-four game tests and the twenty-nine API tests all gate it. A green build deploys the web version, purges the edge cache, builds a signed Android release, installs it on a real Android emulator and runs a launch smoke test — and only a passing smoke promotes the public download link, mirrors the file to Drive and uploads to the store's internal testing track. A version tag is what promotes a build to production. Either way an email arrives saying "ready" or "BLOCKED", with the reason.

Seeing it, not assuming it. A game that renders on a canvas shows nothing to a script that reads the page, so verification is done with real eyes: a GPU browser and a real Android emulator that are driven, screenshotted and checked. The picture at the top of this page was made that way — an agent opened the live site, waited for the first frame, tapped START with real touch events, played a round, and captured it.