
Implement a leveling system for the individual characters with an xp system.
It would give more incentive to fight the COGs and make it so you can use skill points to unlock and level up certain “Perks”.
Think like improved reload speed, health and stamina increases, the ability to slide from a sprint, improved on foot move speed, etc.
I disagree entirely with some games concepts of level locking research and craftables, but it’d be nice to have your character evolve through infantry combat much like your drill rig evolves through exploration and upgrades

what about a research tree, fueled by the heads from the COGs?

That’s actually an even better idea. Would give another end game use for the heads outside of research crafting. Each type could be for a different research skill. Maybe something like: Mil - combat, research - health/stamina/move speed (character), construction - tool health, speed, effectiveness (maybe more ore per vein for each level).
There’s a million things you could add, but using the heads wouldn’t just make it a “passive” xp pool, it’d make it so you have to target certain types to level that certain skill set. I love that idea

why thank you, have my upvote

make it so once you beat it the COGs come back and try to set up new laser devices that you can go and attack