Hell Fighter

"Hell Fighter is a fast action combination of space craft simulation, arcade scroller, and tactical gameplay... all brought onto a single battlefield. As an internet multiplayer game, you control one of the ships in combat on a network server. Fighters, capital ships, bases, merchants, freighters, and other units appear in the game... they may be controlled by players or AI. They may be on your side... or they may be the enemy. Hell Fighter is freeware. I write this game because I wanted a game like this to exist, and there is just nothing else like it out there. - David Peterson"

http://www.dracova.com/hellfighter/