Another Silverlight based game at the excellent site: Mashooo
Vector Space Armada, sounds good.
The initial feeling was one of the 1980s and playing the vector games in an arcade. Then my mouse ran away from the screen and the little vector space ship went away from the training track. This lowered the fun factor. Something else happened. Then the faint ship on dark background killed my addiction factor.
With some tweaks like wider lines, keep the mouse cursor on the screen no matter what the end user does are two of the quick fixes that would raise the scores quickly.
Overall I would rate this game as:
Addicting: ** out of *****
Fun: ** out of *****