This is great, but I wish it was longer. The first 23 levels are pretty easy and it tells you what properties to use, then it drops you into a really difficult level with no hints. It would be nice if it built up to that with some medium difficulty levels.
His code is pretty damn awesome. Open the site in chrome. Open web inspector.
Paste this into the console:
levels.push({
name: 'super secret-1',
instructions: 'This is a secret level you get no instructions.',
board: 'rggggyyyyy',
style: {'flex-direction': 'column-reverse', 'flex-wrap': 'wrap-reverse', 'align-content': 'space-between', 'justify-content': 'center'},
before: "#pond {\n display: flex;\n",
after: "}",
});
Proceed to the secret 25th level! You can create your own levels, and make a pull request to his git repository if you really want to add some interesting practice levels. Just modify levels.js.
haha, yup, you'd have to modify 'style' attribute in the new level definition. I didn't test but i'm assuming it determines the position of the lily pads.
You can reference his levels here when trying to create your own.