"She's probably dead. Or worse, evil. Or worse, in this game."
Bears Are Bad News: He gets antsy whenever he encounters a bear in his Baldur's Gate playthrough, because one bear is tough enough to absolutely wreck his party. When a group of druids summons bears (plural) in a fight, he absolutely loses it.
Bigger Bad: In his Let's Play of Super Mario World (a homebrew game for the Mega Drive, not that one), the fact Bowser is swiftly disposed of only for Mario to fight a slew of other bosses leads Kiko to believe that Barnett the Elephant, the final boss of the game, has been the real mastermind in the Mushroom Kingdom all along. Bowser was just a lackey.
Big "WHAT?!": In The Legend of Kyrandia 2: Hand of Fate, Kiko is sent on a fool's quest to pay various questionable people for a trip to the center of the earth. Then he discovers that he could simply have had Zanthia jump down an air vent. His reaction is this.
Also whenever he's reading dialogue, he'll do some voice-acting.
Butt Monkey: Keith in the UFO: Aftermath series, who both starts out as the slowest character on the team and has an accent that's as thick as molasses, making him an easy target for Kiko's wisecracks.
As the game progresses, he turns out as one of the most valuable members of the team though. His place as Butt Monkey is subsequently taken by Gaston II
Kikoskia: Keith has managed to make something of himself! You, Gaston II, are a load stone made of uranium!
Destructive Saviour: In his Mount and Blade playthrough, Kikoskia's character attempts to defend a peasant village from bandits in his first foray into the wider world. He wins by virtue of the fact that his character is literally the last man standing on the battlefield, all of the peasants having been killed or knocked out during the fight.
He gave Enemy Unknown another go, though, and other than the quick loss of SubZero, did MUCH better, actually winning the game. Granted, he didn't do a challenge that time around, but considering how unforgiving these games are, that's hardly something worthy of shame. If anything, it's proof he's still sane.
In a more meta example, his new X-COM playthrough.
Hollywood Tactics: In full force for his first playthroughs of UFO: Enemy Unknown and Terror from the Deep. He gets better in later playthroughs of X-COM and similar games, though, taking advantage of cover, tactics, teamwork, and combined arms.
Iolo is actually the thief (not the Avatar) - This is because of a twist in the Ultima VII game engine which doesn't allow the Avatar to steal, but other members of the party can. This leads to a Running Gag.
Also from his Baldur's Gate Enhanced Edition playthrough: "You'll notice that we're stealing blindly from everyone — 'cuz I'm a goit."
In his X-COM playthroughs, he always names one of his squad members Barry, whose sole duty is to run ahead of the squad and find aliens via getting shot at. After he inevitably dies, another trooper gets named Barry, and the process continues.
In his playthrough of Star Trek: 25th Anniversary, the caption for his video of his first away mission reads "Who wants to take bets as to how many times I can get the redshirt killed on this mission alone?".