Hi imzadi, welcome to the forums!
As Mal said, resolutions below 1024x768 are not supported; this is because the interface is designed to be extensible, allowing the interface to be stretched out, filled, and sharpened as the resolution increases. Due to the way it is programmed, the game counter-intuitively looks better on extremely high resolutions, even though it is technically stretching everything out.
As there is so much information presented on the screen though, there just isn't enough room for everything to be displayed on resolutions lower than 1024x768, which is why anything lower isn't supported.
However, there is a very small light at the end of the tunnel. To improve performance on lower-end computers, Mike has plans to implement some new graphics options in the options menu; these include things like turning off the planet animations. I'm not sure what the full list of options will be, but there *may* be options to turn some of the game information off - so if there is, you *may* be able to squeeze the game onto a smaller interface. These new options will be implemented in the next update, although I don't know when that will be as Mike is working on refactoring the entire game code in a bid to both improve game performance and to fix some annoying bugs.
. An experienced player should not need to read the actual text to play the game but do it "by-heart" and via symbols. Maybe one could trim the game so the in-game text would be completely "neglectable". Could be difficult though..