I'm addicted to this game.
Playable Characters:
* denotes that the person is "secret" and must be won
An odd thing I've noticed about the game: apart from being addictive, players almost always choose one fighter from the above list and stick with him/her fanatically throughout their SSB careers. My player is always Samus†, my little brother uses Pikachu always, and a friend of mine is obsessed with Kirby. Whether this is a common thing or not, I don't know; /msg me if you always use one guy over the rest.
brief summary of controls:
The analog stick controls what you'd expect it to. All of the C buttons- the little yellow deals- do the same thing; press once to jump, press again (and again and again, for some players such as Kirby) to jump again in mid-air. B shoots (or in some cases, charges) your projectile weapon. A makes your guy punch, kick, or something short ranged. The R button executes a grab, and once a player has been grabbed you can throw them by pressing left or right. Combos can be executed in most cases by pressing up and B or A. Pressing down and B does what I call the vertical attack- it causes damage to people either above or below you, depending on which person you use. Other attacks can be found by randomly punching buttons and sticking with what seems to work. (Perhaps this explains why players often stick with one and only one character- once you've got the moves memorized for one guy, it's easier simply to stick with him.)
Fighters can use such weapons as Koopa Troopa shells (both the normal green types and the heatseeking reds), Light Sabers, laser guns, bob-ombs, Donkey Kong hammers, and the immortal Star.
If you haven't played this game, you owe it to yourself to go out and rent it. Get a few extra controllers and invite some friends over and do an all-out Mario Battle Royale.
Another fun element of the game that I won't delve in to is pausing the game and rotating around players Matrix Bullet Time style, and attempting to pause the game at the crucial moment that Luigi appears to be humping Pikachu or that Samus has a critically placed Light Saber. Hours of fun result.
† sfc points out that Samus can't possible be the "Guy" I always use (as previously stated), seeing as how she's a female. I apoligize deeply.