If you have a non standard keyboard, you can play the game using the arrow keys,. We will add a keyboard config option in a future update. (I am not sure of the best way to make that work...so it might take a little while)
Difficulty Update!
Thanks for letting me know that the game is a bit more challenging than you would expect!
I think the difficulty should be related to learning the characters and not switching buttons! as a result I am going to add a preview of what is coming up to make the game easier to play (as far as reaction times go). Hopefully this will solve any issues people are having.
I have also removed the tutorial from the Katakana mode as it was unnecessary, thanks for your feedback so far!
I have been working on the update since the game went live, and hope to have it finished in the next 24 hours or so!