That game is called Swarm Gold.
http://space-galaga.games-here.com/swarm_galaga.html
Ive played it and as far as I can tell its pretty much a derivative of asteroids but the ship isnt stationary it travels around. The game were making incorporates the same kind of overhead camera with the ship positioned in the middle, and it functions the same way.
This isnt something that company can sue us for is it? The story we have is our own original work and so is our content. So could we still complete this game and release it commercially without facing any legal ramifications?
Thanks for any replies I appreciate it.