layered 2d game - background layer...

For a background layer, should I draw a bunch of scaled-down sprites, to a screen-sized render-target, or draw full-sized sprites to a big render target, and scale IT down instead?

I feel like I want to draw one BIG render target, to make everything easy. And Since I already need normal maps, I feel mip-maps would be a work load increase… And I don’t know that it would help me that much.

Personally for 2D games I normally do scaled-down sprites to a screen-sized render target. I don’t know the inner workings of SpriteBatch or Monogame but intuitively to me, that would seem to be more performant because you’re not blitting extra pixels to screen that you don’t need. I remember back in my C++ days it was a lot more efficient to draw to a smaller screen size. Things have changed over the years so I could be wrong today and Monogame might have an efficient way of doing it now, but that’s my take.

Well usually draw what you need at the scale you need, if your game is not resource intensive you can use any size , it won’t matter much. If you have a lot of sprites to render and performance suffers then you can choose to render just smaller sprites and then scale up the last render target, it depends how much detail you want to preserve. Do what you feel first then find what is your bottleneck, since you will be iterating a lot doing a game over optimizing is a waste of time, especially if you end up not using what you optimized at the end.