Pretty cool :) I'm sure you learned alot implementing the different things for this game.
The timer text is a bit difficult to read though - I think it is a combination of the font and the number jumping a alot - maybe it would be easier to read without decimal points? Or at least just a constant number of decimal points so that the seconds value is always in the same spot in the screen.
I did not play the game before the hit marker, but I think it has added a lot of value to the game.