Loved playing this, had fun hurting my hands! What a simple but effective concept that has a good amount of replayability. I found that mashing the three keys was the best strategy lol. I couldn't get higher than 170 but managed 351 by mashing.
I think my only criticism is that music and some sound effects would have made it much better. Also maybe being able to skip the text intro or speed it up somehow if I have seen it before.
Great game!