Skyfall saves your high score using the browser's localStorage API — a small amount of data the browser keeps on your device, tied to this specific site. No account, no server round-trip, no personal information involved. When your round ends, we compare the final score to whatever's currently stored and overwrite it if you've beaten it.
The trade-off with this approach is scope: your high score is tied to that browser, on that device. It won't follow you from Chrome to Safari, from your phone to your laptop, or survive if you clear that browser's site data. We chose this deliberately rather than building account infrastructure, for a few reasons. An account system means a database, authentication, password resets, and — critically — a reason to collect an email address from someone who just wanted to shoot some birds for two minutes. That's a lot of surface area and a lot of data collection for a feature whose only job is remembering one number.
It's not a decision we consider permanent. If enough players want cross-device high scores or a real leaderboard, that's a feature we'd build deliberately, with a clear explanation of what data it requires and why — not something we'd bolt on quietly. For now, localStorage gets the core of what a high score is for (something to beat on your next run) without asking for anything in return.