Shmups are one of the only game genres that alter the display space regularly. Depending on which direction the shmup travels in, there can sometimes be large static blocks on the sides of the screen. In the beginnings of the bottom to top shmups, they would often leave the side of the 4:3 screens out to create a 3:4 display space. This alteration would allow the player to see more of what lies ahead than what was around them, since what comes next is a more important part of a shmup than what is here and now.
Left to right Shmup example
Bottom to top Shmup example
I believe this element is simply a logical progression of the genre. It is not fun to play when needed information is hidden from you but unnecessary information is shoved in its place. I feel this should be placed into our current WIP shmups in class because in our testing I have felt extremely limited in view. But that begs the question, what do you put on the sides? We could implement score and or waves that could be displayed there, we could also display ammo values if we implemented those. However adding these things in would still leave a large amount of negative space that could easily cause the game to feel unpolished and raw. The gamasutra article by Luke McMillan gives details to the positives and negatives of left to right and bottom to top shmups. He details the more common trends and the small things that some shmups did that broke the walls of shmups at the time. He speaks about Zero Gunner and how it uses an unorthodox looking and aiming style, allowing the player to rotate their ship 360 degrees while flying forwards. He also talks about viewpoint that travels bottom left to top right in an isometric style, which gave an interesting but slightly disorienting perspective on shmups. You can find it and read more HERE. However, from what it appears, there is no right direction to scroll in and no proper way to do any part of a shmup, but when scrolling up, it’s a good idea to limit the side views so that players don’t focus too much on unnecessary parts of the screen. I plan on implementing these view limiters before shipping so that our WIP shmup feels much more like a legitimate shmup.