I am not sure, what that restriction would prevent the game from running in full screen when you change your monitor to vertical orientation?

Originally posted by Kitsune:

If I rotate my monitor to a vertical orientation can I play this game in full screen?

I'm pretty sure I did with either Reflex or Kamui on my windows tablet. I'm sure shmupsystem 11 would know and probably has a thread confirming or denying it too so I'd check there

Just got this game on a sale and had an issue running it full screen vertically where it wouldn't take up the entire screen, it was letter boxed all the way around. To answer your question if you gave up back in 2015 and for people with my issue: YES but...The resolution of the game would be stretched out if it took up an entire 1920x1080 vertically oriented screen. To get it to fill up as much as possible vertically oriented without being stretched out, run it rotated left or right at 640x480 with the 16:9 Display Support OFF (unchecked).