A video game that you become enthralled with to the point where you sever all ties with family, friends, and even food to play, because it is that amazing.
I for one have spent a lot of time playing video games, and I have to say, no two games captivated me like Grand Theft Auto 3 and Vice City. I devoted months of time over those games, they were all I could think about. And all the controversy over the game's content made me love them more, I could drool. So, my vote would go to the GTA's any day nad twice on Sunday.
A gameasm is what happens when you've played games for so long during a gaming session that you suddenly don't feel like playing anymore. This is like during sex when you can't do it anymore due to orgasm.
"Dude, me and and the guys played Brawl so long that we gameasm'd and then went to Chuck's donuts for some eats."