Great work! The control is smooth and good to play, I liked that.
I just felt that the game could have a difficulty curve, seems like the amount of knives don't change over the curse of the run, nor their speed increases, that would introduce a bit more of challenge. I was also able to cheese the game by just standing in the ground all the time and doing occasional jumps to avoid the bottom knife.
But overall the game is really well done, congrats!