I'm a bit lost on how the resolution for this should work. Is it 64x64 grids of a specific size?
I'm thinking the actual screen pixels are irrelevant as long it is is a screen with a 64x64 grid of blocks where each block is 1 color.
Also - the movement must allow reflect the 64 x 64 so that no one can use higher resolution for smooth movement of those pixels.
Yup, as long as it's 64 x 64 grid emulating 64x64 pixel resolution.
Can I submit more than one game?
If I remember correctly, Itch.io allows this by default. I do not know if it can be turned off, and the rules don't explicitly deny it (at least, I don't think they do, I'd have to double check to be sure), so I think yes.
