I just re-found one of my favorite arcade shooters. I remember playing it in the arcades when I was a kid, but I couldn't remember the title until today. It's Strike Force, an awesome game from Midway that's a hybrid of Stargate, Defender and NARC. The game is not perfect, but it's great two-player action. If you've never tried it before, give it a shot on MAME, or if that's not your thing, try your local arcade. BTW, the game is from 1991.