Before the FPS
games in computer
s and the side scrolling shoot-em-ups
in video game console
s, video arcade
s have vertical scrolling shoot-em-ups. Most of these games have a tilted monitor, and they have a bird's eye view
of a main character shooting
bad guys. They lasted a long time, with Space Invaders
, and Galaga
in the 1970's to later games like SNK
's Guerilla War
in the 80's and 90's, and so on...
However, they don't translate well to home console systems in the 80's (NES and the Sega Master System) and the 16-bit consoles (SNES and the Sega Genesis) of the 90's because of the screens turned back to the horizontal rectangular orientation in TVs. That's where the side scrolling shoot-em-ups start to be popular in consoles.