>>18776
That is a nice question you have got here, OP. I'll give you my tips, thoughts and opinions. Some of them may already be written, but I will give my point of view on these, anyway.
1. The whole setting and mood by themselves must be somewhat underwhelming. Underwhelmingly realistic. Everything primarily should be focused on (but not limit its focus to) realism, stoicism, fatalism.
Most of the characters (NPC, players) should not be excepting anything outstanding, but only the worst possible (and something even worse could happen anyway. In "realistic" military science fiction something bad should have a great chance to happen); they should not be hyped too much. Examples of what I mean:
>Huh? One of our squadrons' rookie turns out to be a total natural-born ace that somehow destroyed (finished off) a few (damaged) enemy machines? It would be a shame if this hotshot gets hit by a stray bullet on his next mission (He probably will);
>We've got a special team that tests experimental units in real combat? They are going on a mission tomorrow? Honestly, if they went on our old first-generation robots, they would at least feel more safe. (One day later, half of the prototypes malfunctioned because of the excessive stress during battle; Some test pilots escaped, few got captured, the others died in horror and despair);
>We can choose our loadout with some regulations so that we can conduct operations efficiently:
>I carry little ammo with me so that no lucky hit will make go boon. And I can find myself some more on the battlefield. Maybe even a new gun from my enemy's dead, cold hands. The more the less, as they say (but later I will regret that as I find myself pinned down by enemy marksmen, unable to return fire as close-quarter combat units move towards me);
>I carry lots of ammo with me so that I won't find myself unable to continue combat (but in the end a piece of shrapnel forces its way through the vents right into the ammo box and I die in a dreadful, violent explosion);
>I carry a moderate amount of ammunition. I won't suffer from being out of ammo or getting blown up (and then, during an intense skirmish, I get hit into the ammo storage. The explosion is not that bad, I just got my mechanical manipulator severely damaged. The main problem are the close-quarter combat units that want to finish me off before the marksmen do.
>We can't really choose our loadout. Everything is based on our roles and skills, regulated by standards that strive for most efficiency and survivability of our pilots. Quartermaster gives us what he is ordered to (But later deadbrain bureaucrats and "military experts" make us go into combat in almost unarmed machines for the sake of saving resources and getting bonus money for "efficiency", and we can't do anything but to obey and serve, else we will get shot).
2. Consider Real Robots (I will be referring to Real Robots mostly as to humanoid bipeds) as a distinct type of a military vehicle. By this I want you to consider the following:
>Real Robots should be customizable and modular (just like any modern armored vehicle) to be ready to get prepared to mostly anything: interchangeable legs (horse-like legs to move through swamps or getting some stable ground under hoofs on mountain rocks? Average feet for urban areas? Blocky stompers for assault units? 4 thick legs for reliability and stability while shooting with artillery arms? Tank treads for speed?), weapons, armor, et cetera.
>Real Robots can't just fight on their own. You need infantry support, air support n' stuff. And don't forget about constant check-ups and maintenance, or else the robots won't be reliable and will be very likely to break down.
>Real Robots are not good in everything. They may excel at maneuverable combat in urban areas, rugged terrain, mountains. They may: use covers, strafe, lie down, duck, sit, crawl, jump, roll. They may be good for fire support, scouting, ambushing, divert actions, probably even spreading chaos and terror if you give them flamethrowers and a wacky paint job. They probably could be used in direct combat for the sake of the Real Robot genre. But there are still types of vehicles that do certain things better than Real Robots.
>Real Robots' main strength lies in their versatility that is based on their modular structure, and the possibility of customization may let them to be the fire support for almost anything (insulate then from water, give them a powerboat instead of legs and you will get yourself a carrier battle group unit; augment their legs with landing gear, give them light aerodynamic armor, install more jets and thrusters and you will get an air support unit and so on).