I've got a mini-itx with 1.80GHz Intel Atom D525 and Intel GMa 950 graphics. It can barely handle several thousand bricks in Blockland.
A general rule of thumb is if its a netbook, it can't game. They aren't designed for games... or really anything other than Internet and office tools.
Atom processors are made for low powered Internet focused devices. The Intel graphics are almost certainly integrated.