Idunno, just doesn't seem that dicey to me. Most games have rng somehow anyway so doesn't really feel like it's adding anything. But as far as the game goes it doesnt really matter.
Anyway, personally I think there's plenty of gameplay overhead for complex beats, especially because you don't have to fire to the beat, like you wont take damage for missing, and as it is the game was fairly easy. So as long as you have patterns that repeat for a while so you can get into them before switching, I think itd be sick. More rewarding as a rhythm game and more unique as a shooter. Just my two cents though.