Apart from being blurry and/or more pixellated (depending on AA settings) due to just being less dense pixel counts, the aspect ratio would be catered for as it is by the game and still produce roughly the same content as it does on other screens.
Some can't deal with aspect ratios at all and slap on black borders, which would really cut into the real estate on a screen like this, others just show a little more or less horizontally or vertically as if you literally covered up parts of a widescreen to create the same aspect ratio, but just imagine that the HUD elements all would get moved into the visible area and scaled accordingly.
It wouldn't look particularly good; I can't imagine anyone actually designs modern/future games for such settings, but (especially games designed for PCs rather than for consoles) they know to be somewhat flexible on such matters. Games that want to include the ability to run on laptops often need to cater for some lower resolutions anyway.