Most likely already suggested................

I was playing DMZ ( kind of overated really) and The cool thing that i liked the most was the players when they charged up on the ground, it looked like the ground was shaking and little rocks were flying up. That is a good realism thing that ESF should think about. ( Even though ESf still Kicks @ss)

Look around for the post that Darktooth asks for suggestions and demonstrates the ability of the particle engine. A clip of SOS's powerup sequence was posted there.