Is this the law

I saw some gaming websites (iwin, shockwave, spintop, etc) having time limits 60 minutes or more. Is this us law? gaming law. basic law? Is there a law om gaming with 60 min. trial?

No law, just basic capitalism. Give player's enough time to get their feet wet with a game, but not enough time for them to get enough out of it unless you buy the full version.

I d/l the trial version of B-17 several months ago, I had about an hour or 30 min with it. It's a flight sim of the bomber, it took me 30 min just to figure out how to take off, by the time I could actually play the game my time ran up.