I have now integrated the particle systems into the main game now...see the screenshots below :)

I haven't added in particle trails yet for the repulsor blasts.

There is also no collision detection yet, but the particles from the explosions (including shock-waves) will check for collisions between asteroids and then do the appropriate actions (theoretically) LOL ;)

Repulsor blasts + beginnings of explosions:

 

Explosions expanded:

 

cheers,
Paul