I'm especially excited to add River Raid.
It happens to be one of my favorite 2600 games -- even my kids love it.
I wasn't sure if it was mainstream enough to make the cut for this guide, but the more I research its place in history the more I feel confident in it.
I can't believe it came out before most mainstream arcade shooters like Xevious and 1942!
Can anyone name another scrolling shooter that came out before River Raid?
Ah found these notes in our Shmups 101
http://www.racketboy.com/retro/shmups-1 ... d-shooters"
The Founding FathersWith the genre’s basic groundwork firmly set, by the early 1980’s more and more of the features we presently associate with shoot-em-ups were beginning to appear. A number of these innovations came courtesy of Western developers: Williams’ Defender debuted as the first “side-view” shooter, as well as the first to feature a screen-covering “smart bomb” special weapon. Atari’s Caverns of Mars, on the other hand, is generally thought to be the first game to implement a “non-infinite” scrolling backdrop, though Activision’s River Raid, which followed on the 2600 console a year later, takes a form more familiar to modern shooter fans. Perhaps the single most important release of the era, however, arrived from Namco’s Japan in the form of Xevious, which introduced background targets that could only be destroyed by a separate secondary weapon (in turn influencing Tehkan, an early incarnation of Tecmo and developer of Star Force) plus more powerful end-level “boss” enemies (which later turned up in Capcom’s own hit 1942)."