Would we be allowed to use like the shapes and stuff that are sprites in Unity 2d or would those count as sprites?

I assume it would mean you have to render the pixels yourself instead of using a sprite, so you'd have to write the rendering code yourself. Or you could make a console based game because that uses characters not sprites.

I don't make the rules, but I'm pretty sure drawing (basic) geometry via code is within the spirit of the limitation.