The short version: the game collects nothing, and this website collects nothing.
Freakopoly runs entirely on your computer. It has no account system, no sign-in, and no analytics or telemetry of any kind. It does not need an internet connection to play, and it does not send anything anywhere — not what you play, not how you play it, and not anything you type into it.
Saved games and any settings you change are written to a folder on your own machine and stay there. Deleting the game removes them.
No analytics, no advertising, no tracking pixels, and no third-party embeds. The one thing stored in your browser is a single flag recording that you confirmed you are 18 or older, so the notice does not appear on every visit. It never leaves your browser and clearing your site data removes it.
If the game or the site ever does collect something — a newsletter sign-up, say — this page will say so plainly before it happens, and it will be something you opt into rather than something switched on by default.