I remember a game I played alongside Samurai Shodown II for a little bit. It was a side-scrolling PC game where your character was a guy wearing black stormtrooper-like armor, but with no helmet, had a sword and also guns and had to kill 2-legged walkers that looked like AT-STs but with a longer head like Alien Xenomorphs have. You had regular enemy guys to kill too (they had armor just like you did), not just the walkers. At the beginning of the level, you were dropped from a futuristic chopper in a dark urban looking area and just side scrolled killing enemies until the final. You had to climb buildings too.
The boss for the first level was a bigger walker, crouching and firing round plasma blasts at you, he occupied almost all the right side height & about 1 third of the length, you had to jump to avoid his blasts and fire at him or get close to slash with your sword.
I think your character was a cop actually, but I'm not sure. It was from the 90s, it required something like Pentium II to play. Resolution was something like 640x480. Maybe lower like Diablo 1's 320x240, but not sure. Looked from about the same year as Samurai Shodown II, which is from 94, so give or take a few.
EDIT: Following the Samurai Shodown II lead, I found Gunforce 2 (Metal Slug predecessor), which has at minute 7:44 here https://www.youtube.com/watch?v=L2KP4rjACXQ a model very similar to my mechs, they have the same art of the head, legs, how they land with the head down and rise it, alongside the joint movement. My game however was 100% on Windows, not only for consoles.