Hmm.. yea you will be processing more pixels so that will give you a hit. But most modern graphics cards should eat that up no problem. Maybe not on mobile though.
I wouldn’t have thought the hit would be compounded by layout complexity though (unless you are stacking a lot of things on top of one another) as you are still processing the same number pixels and anything outside the window is not drawn.
anyway i recall when i made a low res platformer I had similar issue and did this
try a simple lerp
https://www.scirra.com/tutorials/626/ma ... ing-camera
but use lerp like this ( a = lerp(a, b, 1 - f ^ dt) ) as described here
https://www.construct.net/fr/blogs/ashl ... a-time-924
but then the trick is to stop the lerping camera from trying to complete the lerp all the way to the player
so stop it when it is 80 % 90 % there , this stops the slow lerping from pixel to pixel causing jumping around.
there are a few ways to do this , maybe mess with the formula above or just have a large hidden collision sprite that stops the lerp
there are lots of other things you could do to smooth out camera and limit unwanted movement
camera systems can get real complex.
AND/OR you could scale up all you assets layout and window size by a factor of 2 or 4 etc
this will allow you to increase the movement resolution but still fake low resolution and without using fullscreen scaling high,
not 100% but i think many new pixel art games take this approach, (also allows high res lighting and a soft anti aliasing (linear sampling.)