What I'd like to see is a report of keys I need to work on. Or the game could just emphasize them in challenge rounds. Even after twenty years of touch typing and a hacked keyboard [0], I still have trouble with the 'xcvb' cluster. So yeah, I guess I know my problem area.
Update, it was the 'j' that did me in. I couldn't decide if it was an 'i' or an 'l'. Impact culpa.