--- title: "SPRONIA — an aerial duel in the browser | G&G Technologies" description: "You fly by flapping, and on contact the higher rider wins. It runs in the browser: no account, no server, and the high score table stays on this computer." publisher: "G&G Technologies" lang: en canonical: https://ggtechnologies.sm/en/app/spronia/ translation: https://ggtechnologies.sm/app/spronia/index.md --- # You climb by flapping. *Free and open source* Two directions, a flap and a shield. The faster you flap the higher you go — and on contact the higher spur wins. The spur is the dash ahead of the nose. Below there is molten metal. Category · [Games](https://ggtechnologies.sm/en/app/?tag=svago) - [Open the app](https://ggtechnologies.sm/app/spronia/run/) - [Source code](https://github.com/G-G-Technologies-Srl/g-g-technologies-srl.github.io/tree/main/app/spronia) *Why a second game* ## One rule, and you watch it happen. The apps we publish share a technical constraint rather than a subject: they run on the machine of whoever opens them and send nothing anywhere. A game demonstrates that to everybody who will never open a file of measurements. Here the game has one rule and it fits on a line: when two riders touch, the one whose spur is higher stays airborne and the other does not. Everything else — the inertia, the ledges, the metal on the floor — exists to make being higher at the right moment difficult. Flight works the way a flapping machine flies: there is no command for up, there is the rate at which you flap. It is the mechanic that makes the genre recognisable, and it is also why it takes ten seconds to learn and rather longer to master. ![The app running in the browser.](https://ggtechnologies.sm/assets/shot-spronia-en.png) ### What it does - You fly by flapping: no key climbs on its own, and holding one down counts as a single flap. - On contact the higher spur wins. Level with each other and both bounce away. - Seven ledges across six heights, and the two lowest are short: between them there is nothing but molten metal, so flying low is a choice and not a rest. - The field wraps horizontally: leave on the right and you come back on the left. - Whatever you unseat leaves a cell: collect it once it has touched down, or it hatches and comes back a class higher. - A fire shield that burns whatever you touch, however you touch it: three seconds, and back after ten. - Waves with rules of their own — cells only, survival, team, duel — announced as they begin. - Two things come out of the molten metal when a wave runs too long: a claw that grabs whoever flies low, and a fireball spat into the air that comes down wherever it finds open space. - A high score table, counters and a coin slot as on an arcade cabinet, with the scores kept in this browser and exportable. - Sound generated by the browser, with no audio file to download. - Two play on one keyboard, or one on the keyboard and one on a gamepad, and the keys can be changed if yours will not take the combination. - After the first visit it works with no connection, in Italian and English, with light and dark themes, and installs as an application. ### What it does not do - It sends nothing anywhere: no account, and no score on a server of ours. - There is no worldwide high score table, for the same reason. - Two players need a keyboard or a gamepad: four thumbs do not fit on a phone. - There are no purchases and no advertising. *In brief* #### Status Complete, from the first wave to the sixtieth: that each one can be emptied is verified by a check that runs in the code on every change. #### Controls A and D to turn, W to flap, S for the shield — or press the field on the side you want to go, and every press is a flap. The keys can be changed. #### Data Stays on your computer. After the page has loaded the app makes no network requests. #### Two players On one keyboard, or with a gamepad. #### Screen Fixed, with no scrolling. On a phone it wants to be held sideways. #### Content There is fighting. Whoever loses burns and sinks into the molten metal, and the fire shield sometimes takes a head off, blood and all. It is all drawn in large pixels, but it is worth knowing before handing it to a child. #### High scores They stay in this browser, on this computer, like a cabinet's. You can export them to a file and put them back elsewhere. #### Sound The browser generates it as you play: there is no audio file to download. It switches off from the bar at the top. #### Offline After the first visit it works without a connection. #### Updates On their own. Next to the app's name is its version; when a new one is ready, the line says so and you tap it to switch. To know, the browser re-reads one file of the app from our site, https://ggtechnologies.sm/app/spronia/run/sw.js: it is the only request after loading, and it carries nothing of yours. #### Languages Italian and English, following the browser's language. #### Licence Apache-2.0. The code is public and reusable, including commercially. **Version** 1.8.4 · **Updated** 23 September 2026 · **Licence** Apache-2.0 · [Source code](https://github.com/G-G-Technologies-Srl/g-g-technologies-srl.github.io/tree/main/app/spronia) *FAQ* ## Frequently asked questions ### How do you gain height? By flapping: that is the mechanic. Your height depends on how fast you beat your wings, so hovering is something you are doing rather than a state you are in. With a key you could hold, the height rule would become trivial — and the height rule is the only rule there is. ### Where does the game come from? It is original, written by us, in the tradition of the flying-joust arcade games of the early 1980s. The mechanics of a genre appear in dozens of games and belong to the genre; the map, the numbers, the artwork and the code are ours, and the only marks here are ours. ### Why is the high score table not shared? Because a shared table needs a server to receive the scores, and these apps do not have one. It is the same choice that makes the game usable with no connection and no account. ### Can two people play? Yes, on one keyboard or with a gamepad. The two sets of keys sit far apart because many keyboards will not register too many keys held at once, and if yours will not take the combination you can remap them. ### What changes from one wave to the next? The number and class of the enemies, which ledges are there, and every so often the rule itself. A cells-only wave has nothing in the air: they are all on the ground and they hatch if you leave them. A survival wave pays whoever finishes it without dying. With two players there is also the duel, the one moment when hitting the other player is worth points. Whichever it is, the wave says so as it begins. ### Does the coin do anything? Two things. It is the gesture a browser requires before it will let any sound out, so the game needs no “click to enable audio” banner pasted over it. And it counts the games played on this machine, which is the one number a cabinet always knew about itself. Coins are unlimited. ### Can I take the high score table away? Yes. From the table screen you export a readable JSON file and import it wherever you like. With no server that is the only copy there is, so it is worth doing before you change computer or clear the site's data. ### How does the app update, once installed? On its own, and it tells you. Next to the app's name is its version. When a new one is ready the line shows both — the one you have and the one coming — with a green dot: tap it, the app reloads updated and your data stays where it is. If you do not tap it, the new version comes in at the next opening anyway. If you installed the app before this notice existed, the first time is by hand: close every window of the app and open it again; if the version still does not show next to the name, reload the page with Ctrl+F5, or ⌘⇧R on a Mac. From then on the app takes care of it. ### And to remove it? Removing it is the system's job, not the app's: no website can uninstall itself, and that is a good rule. Inside the installed app, next to its name, there is «Installed»: tap it and it tells you where the command is on your system. One point worth knowing: removing the app leaves the data where it is, and deleting the data leaves the app where it is. If you no longer need the data, export the archive first. ## Need something that runs locally? If you have a case where the data must not leave the machine using it, describe it to us. A person from the team replies, not an automated message. - [Email us](mailto:info@ggtechnologies.sm?subject=SPRONIA%20%E2%80%94%20applications%20that%20run%20locally) - [Call us](tel:+3780549900824) ### [On-premise AI](https://ggtechnologies.sm/en/services/on-premise-ai/) How to choose between fully local, hybrid and cloud, starting from your data. ### [Robotics & Automation](https://ggtechnologies.sm/en/services/robotics-automation/) Automation at the machine, integration with your systems, downtime measured. ### [DigiSense®](https://ggtechnologies.sm/en/digisense/) What sits underneath, and why your project does not start from scratch.