I just discovered a new Vim Adventures game, the Vim Adventures Quiz. This is a smaller challenge where you're tested on the number of keystrokes made to fix a text file.
You can type
:help to get instructions for the game and some Vim tips, and
:q to exit. The
:keyboard command allows you to press a key and get a textual description of what it would do in Vim, which is really useful. If you get stuck you can click the icon on the bottom left to display a menu.