I like the concept a lot. Some car racing/track sounds would be fun additions :) But two things really bug me about this.
1) The web page makes me feel like I'm about to download a virus
2) I hate hate hate it when typing instructors make me stop, go back, and fix my mistake. Just log it and let me continue. Or at least stop the cursor so I don't have to completely snap out of it, figure out how far to go back, etc.
CryptoPoops