I haven't actually played Metal Slug 7 yet, so I'm just left to cluelessly bumble my way through what they might represent, submitted by others. Not that that's anything new, though.
These were ripped by Ivo. I originally thought the future soldiers just edited willy-nilly from the original soldier sprites, without much thought to whether they were needed or not, but it turns out they are used, except for the kick. At least, somebody said so. Haven't never played the game, that person's word is all I've got to go on. He or she could say the game has a Giraffe Slug and I, having never played the game, would have to believe. It's an unpleasant scenario to be in, really.
That same person who debunked me (he calls himself @$$h0l3, if that satisfies curiosity) also said that the Protogunner and even the Slug Gunner are totally in the game with full animation but not actually used. See, this is doubly terrible, because I haven't played Metal Slug 6 where the vehicle supposedly appears in the flesh, and I haven't played 7 to know the significance of it being unused, meaning I can't actually speculate in any other way, and am forced to nod my head and say "okay."
Morden looking up doesn't require much thought, though. People have to look up, and it's a free country.
Somebody also said this bubble was unused. If the manual said "COLLECT A BUBBLE TO UNLOCK METAL SLUG ADVANCE: GOOD EDITION" but the bubble was conspicuously missing entirely then this could be astounding news, but it's just a bubble, y'know. And bubbles are trouble.
This is a terrible way to start a new section.