Things that instantly kill your interest in a game
Let see there are several things...
1. Showing me some thing some player pulled off in said game that it was not you or someone you know pull off.
Example: Personally I don't care if some kid from the other side of the country can abuse Flaco's wave-dash, that still do not make me want to play Smash Bros. (Note: I did break down and get Smash Bros Brawl, but only after a smarter friend let me play the game on my own for a day).
2. Comparing a game to another game series I played when you, your self never played the game series in question.
Example: Buddy: "Oh my god you need to get Deus Ex Human Revolution".
The buddy never touched Deus ex machina and is incapable of properly pronouncing the game's name, but that can slide. Buddy: "you like it, it is just like Metal Gear Solid" I looked at him and said "Ever played Metal Gear"? Buddy: "Umm I don't remember playing Metal gear".
3. Spoiling one of the main characters big secret or giving away the plot on a story driven game.
If the Character's secret is obvious I can figure it out on my own thank you very much.
4. Let me play my games at my own pace. Getting me to hurry up playing a story or campaign mode will not want me to get any faster in playing the online multi-player.
5. Making the game's graphics the selling point. I do not care about graphics.
And please do not confuse graphics with visual ascetics. Good graphics do not make a game look good, good visual design makes a game look good.
6. Random dumb crap that pisses me off. EA Titles with there project $10 dollar, BS PC server nonsense and how in general how they think of their customer base. (Origin exclusiveness included), Halo titles (nuff said), The Xbox 360 Kinect. This Better With Kinect thing is bull shit, I already own 1 Wii, why do I need a second one.