The Insane Space Hunter
DECEASED
After pursuing his rampant computer across the cosmos to find it had been the victim of the potent Maverick virus (which his own biological systems rendered him immune to), he gave himself over to the virus to combat his computer while Spam prepared to deal it a final blow. The plan worked, but the Hunter in his crazed, infected state was killed by a deceased Flat Stanley swipe by the computer.

Mawani
DECEASED
Killed by Death (hot pink business cards and all) for reasons detailing to the etheric non-participation realms. I don't know how exactly to explain that in terms of the actual story, so we'll leave it at that.

Popeye
DECEASED
Fell into a trap orchestrated by our friend, the Badger, involving quicksand and a big pooch. Would've been fine if he hadn't choked on the spinach that had saved his life so many times previously.

George de Sand
OUT OF THE BATTLE
Evidently joined Gato and Zeon following the whole Asuka thing's resolution. Oh, and he's not dead. Left the battle.

Sarah
OUT OF THE BATTLE
Offed Mecha Sonic. Then, after fighting with Ffej over the death of her evidently-not-dead husband, she fought against reconstructed versions of dab, Pokemyth, and SimBen 2 and was accidentally cut nearly in half by the lethal edge of Flat Stanley. Now, to save her, the merry group of heroes needed to get the Hunter's armor back from the deranged know-it-all computer hightailing it for the Leyline.
Well, they managed that, at no small cost. The Hunter and Flat Stanley died, but her life was saved. Dropped off on Planet 70 to start searching for her husband, Mega Light X, we'll probably be hearing from her again...

Max
DECEASED
Saw George, Gato, and Asuka off, then ventured off on his own. Saw Sarah and Mecha Sonic falling toward Bob, which he reckoned wouldn't turn out well. Tried to shoot Mecha Sonic out of the sky, but due to low batteries, he was unable to perform that duty. He set a course to intercept them in midair, but in arming himself, he was distracted long enough to be the unfortunate recipient of a Mecha Sonic cannonball dive. Sarah's mechgun blast redirected the falling robot and changed his speed, causing a rather unfortunate meeting of flesh and metal. Whatever was left of him fell off of Mecha Sonic or was burned away as the robot jumped out of the dying ship...

Ffej
OUT OF THE BATTLE
Fought Sarah because she believed him to have killed Mega Light X, who's evidently not dead. Which he did, though like I said, he's not dead. Got his eyebrow singed.
Following that whole episode, he, along with Stanley, the Hunter, and Sarah were attacked by clones of Pokemyth, dab, and SimBen 2. Kicked SimBen in a fit of rage regarding Destruct's overuse in previous BOTPs, causing the war-borg to stumble into (and blow up) the earth dragon. Blew Pokemyth to kingdom come, as well.
Continued to the heart of the Leyline, where the crew fought against the Insane Space Hunter's computer and power armor. After the battle where they lost Flat Stanley, he bowed out of the competition for the Leyline.

Kane
OUT OF THE BATTLE
Was hired to kill ISH, but one sword-toting psychic and a game of volleyball later, he was thought to be dead. It was then discovered that Red, Insaney's sometime love interest (who's really Kane's girl, unfortunately for he who is the protagonist in this little storyline here), had slapped together a fake Kane to go off and die so that nobody would come after him whilst he was recuperating from his battle with Darkness. Then, he and Red left the system for parts unknown.

Ambrosia
WON THE FREAKING BATTLE
Killed Johnny. Then, she adventured through the wilds of Planet Bob, meeting Sarah, The Insane Space Hunter, Ffej, and, unfortunately, a clone of Durandal. After destroying the rampant artificial intelligence, she continued on with what was left of the original participants to the heart of the Leyline itself, where, after a horrific battle with the Quest of Insanity's computer, became the victor of the battle when Ffej bowed out.
Her wish was simply that all the participants that had lost their lives in the battle be revived... though that's just going to start this all over again, as it usually does. :P

Flat Stanley
DECEASED
Used by Kane to partially (and ultimately effectively) behead Leon (in his Darkness form), and then he spun off into the night on Planet Gothax. Then, he got teleported to Bob with Johnny, where he was used once again by Spam to kill the deranged psycho. His bisecting powers brought grief, however, as he was blown to an upside-down vertical position in the ground where he mistakenly cut Sarah nearly in half.
After many apologies, he traveled to the Leyline to fight the Quest of Insanity's computer, where he lost his life to the deranged machine.

Johnny C.
DECEASED
Blew up a lot of heads (including ISH's), but, much to his chargrine, ISH mistakenly replaced his head with Johnny's body. And ran off to find a taco. Fell off later, blew up part of another planet, then got in a tizzy with Flat Stanley on Gothax and was mistakenly thrown to Planet Bob. There, he met Spam, Badger, and Ffej, who fought him. After blowing one of Spam's wings off, shooting Ffej, and causing Badger to deep fry himself to save Spam, Flat Stanley struck again, wielded like a frisbee by Spam. Let's just say that Johnny's not half the man he used to be.

Earthworm Jim
DECEASED
Got killed by Max. "Beheaded." You tell me how that works for a worm.

Anavel Gato
OUT OF THE BATTLE
Gundam beyond repair, he left the planet with Asuka and George to go back to Zeon. For him, the battle is over..

Mecha Sonic
DECEASED
During his fight with Sarah (after Badger, Spam, and Ffej left), he got jettisoned into space. With Sarah. Battled it out with her while falling through the air, culminating in Sarah changing his trajectory and speed with a charged Mechgun blast, which sent him careening into Max's ship. Where Max became a pincushion after meeting Mecha Sonic's less-than-amiable backside. Ended up being rocketed away from Sarah by the careening ship, but came back to fight Sarah and lost.

Badger
DECEASED
Killed whilst defending Ambrosia against Johnny's BFG. Whacked the blast back at the maniac, he did. Had a spluttering death scene afterward and everything. If nobody had talked to him, he'd have stayed alive, no matter how long it took--NO ONE can die until after they've said their goodbyes, if they're a major character.

Leon
DECEASED
Killed by Flat Stanley, who was thrown by Kane. Destroyed a good part of the planet Gothax, though.