- new graphic engine that allows to play in greater resolutions (example: 1280x960), but it needs a 3D card with at least 16 MB of memory
- new menus
- updated tournament mode (with the race, qualifications, tournament in double, etc...)
- the grass gets used during tournament
- and a few other little things
[click on pictures to see them in real size]
It'll be free for all people for bought TE2004 in the last 60 days preceding the release of TE2005, and it'll be 50% off for all other TE2004 users.
So yes, you should have it for free.