An online multiplayer game in which one player starts weak, without any armor or weapons. His teammate is armed and strong but is under no incentive to help or defend the teammate. After the level is done, they are unlikely to see each other again.
The armed player can opt for altruism or selfishness (no punishment or reward either way). The unarmed player gets to sharpen his negotiation skills to get the armed one's help/protection.
Learn that there are different kinds of people in the world and appreciate the difference.
You can try different roles. The only cost is how each makes you feel.
Learn to see others’ shortcomings with supportive eyes. Hopefully, you will be greeted with the same kindness when the roles get reversed.
Have fun doing (or not) stuff for others.
Experience ocassional sociopathy first hand.
Player A is weak. His mission is to roam the enemy's territory and forage for parts and weapons to build an armed exoskeleton. He pulls a trailer on which the exoskeleton is built (but can't be used during the level). He has to hide/run from the enemy. If caught, he cannot defend himself.
Player B is wearing an exoskeleton and is capable of defending against the enemy. Both players are unofficially on the same team, but player B has no incentive or obligation to help player A. Both players know that there is no reason why player B would help player A.
Both players see each other on the map. They can chat. They get notified when one of them is under attack.
Player B passes the lever either way. He is basically just collecting points killing the enemy.
Room for altruism with player A
Player A can't pass the level unless he builds a sufficiently advanced exoskeleton and pulls it into a difficult-to-access extraction point. He can choose to build an amazing exoskeleton (at no extra points) or one that barely passes the level.
In the next round, player B finds himself in the role of an unarmed forager that has to assemble the next exoskeleton. In the next level, the previous player A's completed exoskeleton is used by some other random person that plays against player B.
In the next level, player A gets an exoskeleton that was made for him by another random player.
You first help a stranger pass the level even though they are building a weapon that will be used against you in the next round. You then rely on volunteer protection from a stranger that finds himself on your team. When it's your time to build, you can go out of your way and build a great exoskeleton for someone else to enjoy or one that barely passes the level. The gameplay largely depends on people's personalities.