Really good "couch" coöperative games are pretty rare. I'm referring to games where you and your buddy sit on the couch, play next to each other and are actually on the same team. There are a lot of great "vs." games, the whole fighting and sports genres are vs. games by and large. But games where you are competing together and the game screen isn't sliced in half in some inscrutable way or one player is vastly more "in the game" than the other are rare. Super Mario Galaxy is an example of this latter foible--two people can play, but one controls Mario and has all the fun, the other can (sigh) point things out on the screen. "Look! A bad guy! (shine shine!)" It's not riveting entertainment.
There are obviously some classics: Contra-style games (Contra, Metal Slug, ), Beat 'em ups (Streets of Rage, Final Fight, Double Dragon) , and some cool variants like Ikari Warriors and Sin & Punishment. But the coöp shmup hasn't always been a viable platform. Having more than one plane/spaceship whatever is nice, but there's not a lot of actual coöperation going on. The goal is to just kill everything.
Game of the Day: PIXELJUNK SHOOTER
Here's one that tcrowe76 broke out last night. It's a top-down shooter--you and your buddy are rescuing miners from some desolated planet, blah blah excuse for lava and diamonds. The coöperative elements are pretty sparse in the early going--it's more a race to get diamonds and dudes. We were getting a little bored, frankly, when things started to get more interesting. There were some gun options added, but only enough for one player--I would get the Magma Gun and tcrowe76 had to steer clear or I'd melt his face off. At the same time, we needed to coordinate to melt the ice in the right places. Later, he could get a Water Cannon and we could team up to make soil where needed or he could cool me off while I blasted my hot cannon.
It got even more interesting with a boss that we really had to team up on to take out--I would yank on the boss' tail, tcrowe76 would blast its bugged out eyes. We actually wondered for a spell as to whether this boss would be beatable in single-player--it'd be a lot tougher, that's for sure.
The controls are a little "thick" but you adjust quickly--there's not an intense amount of action here, so the occasional "whoops" is no biggie. Your partner needs to survive for 10 seconds and you respawn with no worries. The game even shifts upgrades and what not to your partner if you croak.
If you have a PS3 and a friend, the game is very recommendable; and only $10, probably less if you're patient for a sale.