Playing video games on demand, or over a server connection instead of installing a game on your own machine, has become the hot topic of the game industry because of its potential to disrupt the business by cutting retailers out and letting gamers play any game on any kind of computer.The competition is heating up today as Gaikai, another startup in the space, released a video showing how gamers could play any PC game on a Gaikai server without installing it on a home machine. Usually, games have to be installed on a computer because the interaction is so fast that the game can’t depend on connecting to a distant server and getting a reply in a responsive manner. With games played on servers, the home computer simply functions as a display.David Perry, chief executive of Gaikai and a famous game developer, first talked with us about this server-based game technology in March. That was just after OnLive, a well-heeled startup headed by entrepreneur Steve Perlman, showed its technology working during the Game Developers Conference.All of the startups have met with skepticism, since delivering excellent application performance — particularly for heavy-duty apps such as games — is extremely difficult on the Internet, which is pretty patchy in terms of service quality in the U.S. Doubts have been raised about Gaikai in particular since it isn’t as polished as rivals OnLive or Otoy, a Los Angeles-based rival. But Perry said in the video, “I just want people to see we are serious.”“Our goals are really simple, to remove all the friction between hearing about a game and trying it out, to help reduce the cost of gaming, to grow video game audiences, to raise the revenue that publishers and developers can earn, and (most importantly) to make games accessible everywhere,” Perry said. “If the iPhone AppStore has taught us anything, when you make it easy to check things out, you get a billion downloads.”Perry didn’t reveal Gaikai’s business model. But the advantages of playing games stored on s