Ok, here's a "basic" couple of images showing the direction indicators (one selected) the angles of the comets/meteors/asteroids that might come. Finally, and image of the earth when you're just about to lose the game
Scoreboard needs to be added but not get in the way. if two people are playing then the illuminated indicator will be the colour of each player and each player has to only get their colour, or be penalised i guess, or some form of coop play, i've not thought about that much, just been thinking of the main single player mechanics.
whatcha think now that there's 2 thousand words worth of images?