Hi! Thanks for the feedback There is a subtle difficulty curve. As you gain more points, spawn rate increases. I have capped it at minimum 1 second though, if you still feel it's easy, I can increase it more.
Oh, I have replayed it again and yes, there is a subtle one, didn't initially notice. I don't find it particularly easy, nor extremely hard. My high score is 4530, not sure how high that is.
