At the moment, it is very easy to just skip past your score screen on game over and even into another game. A way I suggest combating this is first of all to end the game and fade the sounds out, leaving only the music when you reach your score screen. This will make it easier to hear the score, since if you died, it's more than likely because you were in the midst of a bunch of asteroids, and you still hear them and they're quite loud.
Secondly, a short enforced period of transition between the game over screen and the main menu. That is, when you press OK on the game over screen, A second or two goes by, maybe even with a whoosh or transitional sound, and then you're dropped back onto the menu.