I only noticed this when I found out the resolution I've been using was somehow about 1000 in width. Which is high for pixel art.
But when I changed it to 640:380 resolution, the player is bigger than it should be. The player's sprite is only 32x32 yet it already takes more than half inside the view of the camera. The player and its sprite is 1:1 in scale.
Though I only want to lower the resolution so that a rotated object would be rotated as pixels. The viewport mode in stretch should work but I noticed that even the sprites that I know is in 32:32 pixels, seems to have much more pixels when rotated. I've heard to use the viewport node, but it seems too complicated. And lastly lowering the resolution would increase the performance, probably.