I thought the fish monster was kinda cute, all "
-o- " like it'd just woken up - certainly didn't think it was meant to be an enemy.
If anything I thought it was an anti-pollution message to go with the traditional "Peace Forever!"
Actually the "just woke up" thing is horrifying, never mind.
I wonder if Nazca would've gone with some kind of Atlantean super-technology, with the Rebels throwing their lot in with the enemy (again) to cover the conventional military angle.
Or maybe a new human antagonist group. I'd like to think the sacrifices of MS3's ALL ABOUT LOVE weren't in vain. ;-;
It's something I wonder about, having recently gotten back into the Nazca/SNK trilogy. Whether the shift from 100% army to more and more weird shit was a good idea is debatable, but regardless, the sheer effort they put into never rehashing themselves was formidable. I particularly like how feral MS3's opening stage is, god-awful mutated shit all over the place. In a less self-aware game it'd be some b-horror flick stuff.
As blasphemous as it sounds, MS4 was actually the first one I played in-depth, due to its PS2 conversion getting a surprise NTSCU release (albeit double-packed with MS5). Going back to the Nazca/SNK trilogy, I was on one hand stunned at the boost in artistic quality (there was no replacing those guys), but also surprised at how mild their difficulty curves are compared to MS4, which unmistakably wants you dead by the second boss. So I've always liked the fourth game as "licensed ROMhack / Hardtype" affair.
To be honest, these days it's kinda fun spotting where they stitched everything together from.
My favourite is the Panther Slug, aka one of the hundred-odd slavering mutants burnt alive in MSX's subway!
It's a little vague (second-hand descriptions of interviews, AFAIK), but
here's where I read about MS4's planned fishmen antagonists. Lots of interesting stuff hinted at there, I've meant to investigate properly.