The original Alien Syndrome, released in the mid-80s by Sega, was blatantly influenced by both Aliens and Gauntlet, and while the home games based on the Aliens license weren’t bad, the arcade game released by Konami was a pretty simplistic shooter. Alien Syndrome had large sprawling maps to traverse, which made for a more interesting adventure. In each area, you had to rescue hostages and fight a boss, all with a pretty strict time limit, all while under near constant attack.
Alien Syndrome was ported to pretty much every machine under the sun at the time, but, other than a 3D remake for the PS2 some 15 years later that never saw the light of day in Europe, the series vanished without a trace. That was until 2007, when, when, with virtually no fanfare, a brand new game was released for the Wii and PSP.