Just a small note to Linux users; I managed to get this game running under wine with no tweaking (or winetricks) required.

Specifications:
OS: Ubuntu 12.04
Wine: wine-1.4.1 (this is the version that is packaged in the default repository)

The "widescreen fix" can be applied manually through the registry editor (with wine of course) as per the directions here: http://arparso.de/nexus/forum/index.php?topic=39.0

The registry keys for the screen resolution can be found under:
HKEY_LOCAL_MACHINE/Software/Mithis/Nexus - The Jupiter Incident/

Good Luck!

Nexus is also included in PlayOnLinux - the installer works perfectly, as the game itself (including HD resolution and angle modification, see parent link).