Shot em up! Vertical or Horizontal “side scrolling”?


Question it’s about "Shot em up" style game (For example: Tyrian) also known as Top-Down shooters.

These games in the past mostly exist as top down concept, it means player object can move from the left to the right and enemies start appearing from the top of the screen and moving down to the screen. This concept was probably picked due to the monitors aspect ratios in the past where was most spreaded 4:5.

Also this concept are very popular on mobile phones, because is sometimes more user friendly not using landscape mode when playing.

There was a very little titles, when the concept Top-Down are changed Right-left It means, player object is on left screen side and moving Top and Down, and the enemies moving from right to the left. Also, there is almost no titles on desktops when current aspect ratios are mostly 16:9. Even if some new “Modern” Shot em up is released, mostly pick the Top Down concept.

And my question is, is there any reason for that on Desktops target platform?

I think for the current monitor aspect ratios 16:9 “Right-Left” better fit the gameplay and user experience. Or Am I missing something?