If you have an iPhone, you can download this game in a free version. Looks like it could be fun! From the site:
NoteWorks is a fun game, designed to teach note reading. Up to now, the game was only available for the iPad. We are happy to announce that the iPhone version has just been released.
The free version of the game caters to beginner music students. The full version of NoteWorks was designed for more advanced students, as well as beginners. Please try NoteWorks and let us know what you think.
check it out here: noteworks