Minesweeper

Minesweeper is basically my 'hello world' when I want to learn a new language. First time I did it was when I wanted to learn Java and the second time when I wanted to use HTML5 and the canvas tag.

The Java version was originally written many years back and due to the security changes in browsers might not work for you, but see here if you want to give it a go: Java Minesweeper

The HTML5 version was much more recent and should work on any modern browser: HTML5 Minesweeper