I know that player death consequences is a trodden subject by now but hear me out.
I think that when you die, the remaining robots who you fought before you were killed simply be repaired to full health. This is obviously a non-diagetic gameplay mechanic, which will inevitably upset players who want as much realism as possible, but I have good reasons.
Reason the first: What do you lose when you die? The resources you used to fight the enemy. If the enemy regenerates then when you run back into the fight over and over again (something that most people agree feels like an exploit) then your penalty is that you slowly lose ammo and consumables each time you fail, simply by the act of using them. Simple, challenging, but not unfair.
Reason the second: This mechanic would encourage people to try to escape alive rather than allow themselves to be killed in combat when they are getting overwhelmed. You’ll save the resources by running, returning later and re-engaging strategically until the troublesome enemies in question go down.
The enemy persistence in Generation Zero is obviously designed with the specific intent of players engaging individual enemies over a longer time-frame when compared to other games. So it stands to reason that the player should be encouraged by the mechanics to participate in that mindset by gently punishing recklessness. Engage, flee, reassess, re-engage, over and over until you slowly wittle down the enemy forces blocking your way (be it a bunch of robots or one really big one).
You could take this even further by replenishing destroyed enemies in places where you were killed (or spawning new ones, depending perhaps on how many times you were killed within a certain timeframe). I don’t personally think it needs to be that aggressive, but it wouldn’t hurt to raise the stakes a bit.
Thanks for reading my post, I hope you liked this idea.
Edit: I want to add that I play exclusively in offline singleplayer, so the only caveat is that in co-op this should probably only happen if everyone in the area dies. Alternatively, spawn another robot in a player dies and rushes back (to prevent people from creating a dedicated suicide bomber).