Unused Graphics

Metal Slug 7 stores its graphics in individual .BIN files, typically prefaced with "chr_" or "anm_". They can be opened in the likes of TiledGGD and viewed with a 16-pixel wide canvas.

Alternately, Mr_Beacon00 uncovered an internal sprite viewer in the game, which can be loaded in DeSmuME using these save states. It's prone to freezing on occasion, in which case you can reload the save state. The controls are...

How do you actually activate this, code-wise? No idea. Pester him about it!

These were ripped by Ivo. The animation for kicking down the train carriage door in Metal Slug X (which itself is so obscured as to appear unused) was converted for the future soldiers.

The Slug Gunner and Protogunner are still buried in the game but go totally unused, found in "chr_SL004_PLG.bin" and "chr_SL005_SLG.bin" respectively; cheers to @$$h0l3 for the find. Likely leftovers from Metal Slug 6's code.

A large rotating drill bit, found in "anm_SCREWA.bin"; cheers to Ernesto Aguirre for the find. It has animations for breaking apart and various debris.

Switches with fire and lightning bolt emblems on them, found in "anm_AREASWITCH.bin"; cheers to Ernesto Aguirre for the find. They have secondary frames with partial damage and the 'mouth' open, probably to denote they're activated. Not sure where on earth these could fit in.

A small sprite of the time gate, found in "anm_MINIGATE.bin"; cheers to Ernesto Aguirre for the find. Intended for a cutscene or background detail...?

A large stone wall. A version of this appears as part of the background in the unused 5:8, and later in Metal Slug XX's use of that area. This sprite version was probably intended to move, though. Cheers to Ernesto Aguirre for the discovery.

Somebody also said this bubble was unused. I'll take their word for it. It might have been intended for that strange unused underwater physics stage...?