Build a complete mini-game in a single self-contained index.html file. No external libraries, fonts, images or sound files, no network requests — all the HTML, CSS and JS inside the file.

Choose the genre and the controls yourself. The game must be understandable without instructions.

Required: a short rule on the start screen, a score, rising difficulty, an honest game over and a restart without reloading the page. The game must work both on a computer and on a phone.

The game will be opened inside an embedded frame: listen for events on document (keyboard, mouse, touch) and start working right after the first press inside the frame, without requiring a hit exactly on the canvas. Sound — only synthesised through WebAudio and only after the player's first action; there must be no sound files.

Return ONLY the contents of index.html, complete, in a single code block.
