As I said, the characters are colorful and interesting, which is rare for a game that is mostly multiplayer and not story-driven. It is similar to Team Fortress 2, which has nothing but online multiplayer, yet manages to make characters involving and with their own distinct personality, each with a special weapon to match their personality (more on that in the gameplay section)
The characters in CD:O are as follows:
Sinder, a demon who wants to be in the film industry but is rejected because, well, he's a demon.
Special weapon: Woodchipper.
Violet, a young girl with a jeep who is more or less the host for the show.
Special weapon: Mortar
Fowl Mouth, a 1930's gangster duck who loves money and speaks with a wicked Chicago accent.
Special weapon: Tommygun
Dominique Trix, a french woman who is into kinky stuff. Hot.
Special weapon: Dynamite Crossbow
B.T Bruno, a sort of mix between a construction worker and Elvis, who drives around in a giant bulldozer.
Special weapon: Hammer
Brian, a scientist that is nothing more than a brain in a glass jar with eyes, and tiny legs.
Special weapon: Nuke
Count Earl, A vampire who has the fastest car and speaks with a transylvanian accent. Ah-hah-hah!
Special weapon: Homing missiles
T. Wrecks, a crocodile who also happens to be a diva moviestar, constantly complaining about the events not being in his contract.
Special weapon: Shrink Ray
Whack Angus: An angry bull, seeking revenge on everyone eating cow meat.
Special weapon: Meat Cleavers
Flemming, a genius nerd in a hovercraft who constantly gets bullied around in school and now seeks revenge.
Special weapon: Dual laser guns
Gameplay is reminiscent of Twisted Metal, though, with a more cartoony approach. Cars fighting, you know what I'm talking about. You can drive into boxes with different symbols to grab weapons, and as mentioned earlier, each character has a special weapon. These can be obtained by driving into boxes with an ! on them, but there is a plethora of different weapons aswell, including bombs, missiles,guns, melee weapons, and even a weapon that turns you into a gunship, complete with dual chainguns and a helicopter rotor so you can fly around. It's great fun, especially with a friend.
The control is smooth, R2 accelerates, L2 brakes, X uses weapons (and even when you don't have a weapon you can still attack by throwing an object related to your character), you steer with the left analog stick, the right stick does stunts in different stunts in different directions, which can be used to avoid attacks but also fills up a boost meter, and you can boost with square. It really works.
The graphics are cel shaded and has an interesting art style, where everything is sorta exaggerated (buildings becoming fatter as they become taller etc) and when cars turn, they sorta bend. It actually looks really cool, and the cars have some nice damage effects to them. Doors open, wheels become bent, and my favorite, the trunks of the cars open, revealing what's inside. Fowl Mouth has bags of money, Dominique has a tied-up Gimp guy, it's funny stuff.
There are 13 maps to choose from, 4 'worlds' with 3 maps each. You got the country side, the creepy monster world, space world and jungle world, each based around the 4 unlockable characters Brian, Count Earl, T. Wrecks and Angus (Brian being Space world, Count Earl being Monster world, T. Wrecks being jungle world and Whack Angus being country world).
There are three game modes; your regular checkpoint race, Capture the flag (an interesting concept for a driving game) and smack attack, which is just "Beat the everloving crap out of each other until someones beats up the most"
Now... let's talk flaws. With only 10 characters, the game can get kind of repetetive. Each character only has one campaign, and you'll blaze through each in about half an hour, since they don't differ from regular game modes. You'll get a funny cutscene though.
The maps don't have much variation, and sometimes the driving physics can be really broken. The jumps can cancel out sometimes, but it's minor. The main flaw is probably that, well, there's not enough content. Had it had a few more characters, more game modes, and more variation in the campaigns, it would be one of the best games I've ever played. If you manage to find it, I say check it out.