It goes...
I think its pretty good, but for me I started to get bored at around lvl 19. I played on to lvl 20, but I had to stop. Anyway, I was wondering how you can measure the difficulty, because I found that the lvl difficulty didn't really get much harder, or it got very slowly harder. It should maybe have gotten harder quicker, because after lvl 20 when you are having to press 5000K 5 times it gets a bit tedious. Otherwise, good work.