Is it me or is it really my laptop not completely handling cave story? It gets slower depending how big is the room with assets. I'm using a laptop that is integrated with intel graphics i5200U and it's bad
Your bottleneck probably isn't the processor or graphics card, since that i5200U model you mentioned should be more than powerful enough to run Cave Story, and any computer that has that kind of processor probably has more than enough memory to run Cave Story.
You mentioned DXGL in the thread title. I'm not too familiar with what that is, but based on a cursory Google search, it looks like some kind of alternative to OpenGL. If there was some manual change you made to the graphics libraries that your OS uses to run games, then you could try un-doing those changes.
I guess another question is, are you running the original Cave Story, or are you running a NICALiS port? Seems like your computer should be powerful enough even to run CS+ smoothly, but you never know.
I am running the original Cave Story. I used DXGL because, without it would just be greyscreen.
But yesterday, I noticed that changing its compatibility to windows xp service pack 2 makes it run smoothly. Not completely but still works as long as there are no other program running
(discord is my exception)