The concept is cool and the code is nice and compact. But that comes at a price. Your graphics could be greatly improved. I also think you could get away without the use of assembly by moving the snake itself up and down by changing the Y-Axis coordinates. You would have to use a variable to store the height, but it would greatly improve your graphics and increase speed a tiny bit.
-live the life because the life is good -vivir la vida, porque la vida es buena
-Vie la vie que la vie est bonne -quod est bonum vitae in vita
-lebe das Leben, weil das Leben ist gut -vivere la vita, perché la vita è buona