You'd think NASB to Slap City would be a direct downgrade or upgrade, but I don't think it's either. In fact, I'd even be willing to say that, like I've often said about MVS and NASB, it's not fair to compare them. Like, yeah, they run on the same engine, but so do Syphon Filter and Bubsy 3D. (not saying either of these games is a Bubsy 3D parallel of course, just that NASB is not a sequel to Slap)