Hasty Thesis
Multi-player games aren't just more fun because they're social experiences, but also because they often lack shelf-events which halt progression and cause frustration with the game. Or they provide mechanisms for more easily bypassing them through force-multiplication.
I've been trying to analyze why I have such little interest in playing my single player console games, almost to the point where I'm forcing myself to play them these days just to get some sense of ROI for their cost. Mostly it's because I dread the shelf-level event--a point in the game where difficulty spikes in a weird way and it becomes frustrating to try to advance. I'm at this point in Mirror's Edge, Dead Space, and Resistance right now after a weekend of playing console games. What did I play when I wanted to take a break from this?
- World of Warcraft - still playing this casually (no raiding) and still enjoying myself. Collecting mounts and pets, doing dailies, building rep, running classic content. Completely non-linear, and when I run into problems I just round up a few friends and we go hammer on something together.
- Resistance 2 - only the multi-player in cooperative mode, I still haven't touched the single-player (was waiting until I had beat Resistance 1, which seems unlikely now). This is great fun running through maps, working on teamwork, doing some RPG-lite stuff with your profile, etc. We wiped twice on a particularly difficult part of Bryce Canyon but the forward progress isn't really what this is about so it doesn't really get frustrating. It's more about becoming a better player in your role (which I'm actually doing, surprisingly, given how little framework for educating the player exists in the game).
- Dawn of War - the first one, still a blast to just fire this up for some instant play 2 on 2 or whatever with random races and try to put together a base and army and push for a win on the map. Sure I get creamed sometimes (I'm terrible with Orks for instance) but I can just reload a map and try another setup. Again, no linearity to get blocked.
Corollary: the other genre I spend a ton of time on is single-player RPGs, and I think they have a slightly modified but similar quality to the MP games, in that you can grind in them. If some particular section is too difficult, well I can just grind for XP and gold for a few hours and go level up and get better equipment, and suddenly that shelf event is no longer so difficult.