Pong is a 2-player game.
From its very inception, gaming has been made to be enjoyed with other people. You’d be hard-pressed to find a console without a second controller port and, nowadays, games can be played with other people from across the world through the interwebs. Yet, I find myself always struggling with enjoying games when I play them cooperatively and this made assembling a list about the exceptions quite the challenge.

Players have to take turns being in control while playing Donkey Kong Country in co-op.
Co-op seems like an easy recipe for success. You have a good game, you let people play it together, and now more people are having fun and amplifying each other’s enjoyment. Instead of a competitive match in which 3 out of 4 players are losers by necessity, now everybody is working towards a joint victory.
However, this itself is a fallacy. Even if gamers aren’t competing because they are battling each other, co-op still maintains a competitive element. You are working together, sure, but who is working the most? When I play games in co-op, I often feel like I am holding back the team. When you reliably rank at the bottom of the kill list or fall behind the leveling curve, it begins to feel like you might as well not play at all. Even games I love, like Earth Defense Force, become disheartening when you finish a mission and one player has 300 kills compared to your 60. This is not hypothetic, this actually happened the night before I wrote this piece.

In the chaos of Broforce, it’s not uncommon for everybody to die and wait for the lone survivor to rescue them again.
When this feeling sets in, I always get a sense of panic. I become frantic to actually get kills, annoyed when friends are taking down enemies I could have hit if I were a second faster. And when I get desperate to contribute, chances are I just get into more trouble and need saving. Being that guy that constantly needs to be revived or who triggers Game Overs is a guaranteed way to kill any fun you might still be having.
The reverse isn’t fun either. Sure, you feel powerful when you’re carrying an entire team and topping the scoreboard, but then it just feels like you are playing singleplayer with some tag-alongs. I actually had a friend cancel our run through Diablo III, because every combat encounter was just my mage walking into the room and wiping out everything. His melee-based character had no way to keep up or contribute and the game wouldn’t let us up the difficulty any further than we already had.

The strength of Left 4 Dead and Vermintide is that there are too many problems for 1 or 2 players to fix.
The co-op games that I enjoy are ones where players have their own tasks to manage that don’t intrude much. Games where everybody feels like they have a purpose and are being rewarded for it. Games where nobody feels left behind or, heaven forbid, has to actually wait for their turn to play.
Yeah… good luck finding a lot of those.