Like the visuals and effects.  Bit confused, I kept trying to hit the asteroids instead of dodging.  After I figured it out It was pretty fun.  Do the asteroids move towards the player after they hit the earth? or do they roll around on the surface a bit? either way I found myself trying to anticipate where they would roll. 

Initially thought you needed to get beneath the asteroids to protect the earth but once I realised it was just avoid them I found this pretty fun! nice visuals