There are many different variations of Linux, so we'd need to know which one to help you with any sort of depth. When seeking help we ask that you give as much information as possible about your system; full operating system name and version, what CPU you have, what Graphics Card you have (and what drivers you have installed for it), how much RAM you have, etc.
You can find what basic things you need to install to run the game at http://redeclipse.net/install
- but from the sounds of it, you need to install a proper graphics driver in order to access GLX. This varies depending on operating system and graphics card vendor.