The NeoGeo in fact ONLY has sprites. From memory, I believe the backgrounds you see are actually sprites of 32 pixels by 200 or whatever the height is. This is why NeoGeo games have parallax and things so easily - it's just lots of really tall sprites (the NG has no height limit on its sprites).
Minimum sprite size: 1×2
Maximum sprite size: 16×512
Maximum sprites per scanline: 96
Simultaneous scroll planes: 3
