I'm glad you enjoyed the graphics and music so much! These are definitely my stronger areas.
As a Guitar Hero veteran I agree the buttons can be kind of jarring with arrow keys - but this seems to be the standard layout for arrow-based rhythm games like DDR (I did a bit of research!). I hope at least those gamers will find it intuitive... I did try to make it quite forgiving so I'm glad that helped - there's nothing worse than a rhythm game you can't keep up with 🎶