If I am understanding correctly yes you can. Sounds like in the end you're basically just scaling it up. Scaling up is completely fine and I would recommend it so people aren't actually trying to play on 84x48 resolution on modern screens.
Yeah, also have to make sure the big 'pixels' only move in 1/84 steps. This sort of rules out physics engines because they will move everything on a granular level, if you move things yourself you can round to the nearest 'pixel'. In last year's game I stored the position at a precise level, but when it came to actually moving the object I rounded. Then you can get smooth acceleration that still snaps to pixels, rather than speed being clamped to 1, 2, 4, 8 pixels per frame.
Having written that you could use physics, just hide the 'real' object and show an object which takes the real object's position and rounds it before displaying.
Awesome thanks! Yeah im just scaling it up and working from there.
Yeah in testing out the implementation i had to find work arounds to keep everything snapped to the pixel grid and constrained down to the nokia's fps. I ended up turning every pixel into a 1x1 rectangle and the scaling methods in Löve2d seemed to handle it. For the fps i just gated any calls inside the update and draw functions to happen only on the specific frames.
Plus homebrew collision detection are so much easier when you're dealing with movements expresed in integers.