[From PompiDev blog ]
For those of you who are old enough. Remember those days you would go to an arcade? You would play some game on your own, advancing quite a lot in the game. Suddenly you would notice some kid is silently standing by your side, watching you as you play in pure fascination and seriousness. The game turned to be a lot more fun to play when that kid was watching you.
This kind of social playing, or "arcade magic" is absent in online games. You can play with other people all around the world, but it's not the same as like having someone in the same room with you.
I was playing castle crashers on the XBOX with my friend. He didn't really got excited about it, and claimed there was nothing special about CC. I kind of felt the same way and let go of that game(we played the demo). Then a different friend played CC with me. This time he tried to study all the moves, he was quite good at the game and the overall experience of playing the game with him was a lot better. I suddenly felt the game was a lot better than I previously thought.
It might sound obvious, but playing with other people at the same room can make a great difference on your game experience.
I think this was the charm in the arcades, something that has been gone for some time when online gameplay has appeared(at least for me).
But I think for quite some time "same room" gaming have returned, especially with games like guitar hero. And I think game developers should look into the added value of games you can play with other people in the same room. Maybe that is even what made all the music bands games so popular in the first place?