been done to death
There is nothing wrong with a simple styled game, but this is beyond simple... You're green a square (the only color in the game) and you avoid the black dots that slowly fall from the top of the screen and the total frame count is your score... No music (or any sound for that matter) no backgrounds, 2 shapes (if a dot really counts as a shape) , no variety... Just more dots. Add something to it, maybe something as simple as changing the background every 1000 points or whatever. Add power ups, add music. Put in a reason to keep the player playing.