I have read that as long as it is calibrated right, they screen won't burn but, if kids want to play on it, i would say no. Just to be safe. I have a 55" widescreen HDTV and have played games on it sense the day i got it, it has been almost a year and it still has not burned.
I even did a Halo LAN party w. some of my cousins and we played for almost 10 hours straight. Not a single hint of burn in the screen.
P.S. NEVER play video games on a Plasma screen, not only are they expensive but, i did a "test" on one because my cousin helps make them and played for a few hours and it burned in about 5 hrs.