Toaplan produced several landmark 2D Shooting titles in the arcade during the 1980's that today are regarded as some of the earliest and finest examples of the genre. Among those, one title stands out in particular as having established many important ideas that helped define the shooting game genre -- 1985's Tiger-Heli.

You could say that the features which characterize a shooting game today, like the scrolling playfield, screen clearing bombs, weapon upgrade systems, and so on, were probably in some way influenced by one of the titles in this collection.