FromSoftware's Elden Ring has a unique approach to co-op. Instead of other players simply being able to join one's adventures in the Lands Between, it's necessary for Elden Ring players to first progress some in the game, and then they need the Furlcalling Finger Remedy item to see signs left by other players. After that, Elden Ring players can summon people into their world to help them in the game, with the summoned players sticking around until they've successfully helped the host defeat the area's boss.
Elden Ring co-op makes it possible for players to explore large chunks of the Lands Between map together, but generally speaking, most likely use it to get help in boss fights. After all, Elden Ring boss fights are extremely challenging, and the main goal of the game is to progress through the world by defeating all the major bosses. There are certainly a variety of ways that this co-op system could be improved, but one improvement that comes to mind would be implementing a spectator mode.
During Elden Ring boss fights, it's quite possible that summoned co-op players will die at the hands of the boss. Even with three people all fighting an Elden Ring boss at the same time, they may find it difficult to succeed. And it doesn't help that summoned players have less Flask of Crimson Tears uses than the host player, meaning that they can only heal themselves a very limited number of times.
If Elden Ring co-op players die in the middle of battle, they are whisked back to their own world. They will have a few seconds to watch the fight continue, but it's unlikely that they will get to see the conclusion unless the boss was already almost dead. It would be great for the game to implement a spectator mode so that dead co-op players can stick around if they want to see how the fight ends. After all, it can be highly entertaining to watch another player take on some of Elden Ring's more challenging bosses, plus players may be able to learn some strategies that they can apply to their own game.
Beyond that, an Elden Ring spectator mode could be useful for simply watching what other players are doing outside the confines of boss fights and death. Maybe players could find another strange item like the Furlcalling Finger Remedy that allows them to peek in on another player and see what they're doing in the game. Something like this could be added to the game as part of a potential Elden Ring DLC expansion, but to be clear, nothing to this effect has actually been announced at the time of this writing.
Elden Ring is out now for PC, PS4, PS5, Xbox One, and Xbox Series X.