In 1997, Metal Slug: Super Vehicle-001 was ported over to the Playstation to market to the home console players. In order to work properly on a less performant hardware, around half of the sprites were cut down from this port, removing in the process the fluidity and beauty of the original.
To compensate that, the Combat School, Art Gallery and Another Story were introduced as extra little features.

Metal Slug X was also later ported in 2001, and it's pretty much the same deal: less sprites, less fluid, but has a combat school and an art gallery. The tracks are now also in Midi.

The way I used to rip the sprites was by using PSX Vram to read ePSXe's save states.

Sprite ripper Magma Dragoon already did a really useful tutorial back in 2013 that explains how to load saves states onto PSX VRAM, and it is far superior to what I was going to write. So go check it out!

Regarding how these 2 Metal Slugs work on PSX Vram, it's basically the same thing as Kawaks' tileviewer, with the tiles ordered vertically. However, the Another Story sprites from the first MS are already pieced and ready to go.



These unique sprites have 14x14 pixels wide squares around them so that they can be placed on a 16x16px canvas, similar to Kawaks' tiles.