I have found that Laptops are generally no good for high end game play (which most new games require), even the Supposed "Gaming Laptops" are not really that good (compared to a PC half the price) unless you are spending near £800 - £1200+ on a laptop, i would not get one for "gaming use".
Not saying that a laptop costing £600 won’t run new games, for this sort of money you should be able to get dedicated graphics with a descent processor etc, but don’t expect Xbox / PS3 quality smoothed graphics, in most cases you may need to run near half the resolution and switch off other effects as dynamic lighting, filtering etc for it to run properly.
Oh i would suggest getting a cooling stand for it (like a Belkin one about £12) if you are to play games, as laptops get very hot.