Oh dear, Anne - there does seem to be a problem, with that range of cards - I'm so sorry...
See this:
GeForce 6 & GeForce 7 cards
- The GeForce 6 is too slow.
- As of today there is a technical problem on GeForce 7 cards. The whole screen is filled with fog, making the game unplayable. It's unclear whether it's only a bug or a permanent incompatibility. According to DS, Risen has been tested on the GF 7900 before the system requirements were published. Then the problem didn't surface.
- The obvious conclusion is that it doesn't make much sense to buy the game now for GF 6 or GF 7 users.
The latest (non-)update is that both PB and nVidia are investigating the problem.
at
http://www.rpgwatch.com/forums/showthread.php?t=8276There's a whole subforum dedicated to the game at that site, btw.
I do hope for your sake that they resolve this issue soon, hopefully with a patch.

I've currently got an Nvidia 9800GTX, and for me the game runs flawlessly and does look rather pretty. The colour scheme is similar to that of Crysis - rather subdued, and with those kinds of special effects and vegetation. The chraracter models could have been better though, and some of them are repeated over and over, especially the female ones- so there are a few clones walking around....
