Linear, but the combat is good. They have ok stories. You build your party, and go. No, companions like the other I.E. games. I think 1 is all around the better of the two, but I love 2 for its use of a rendition of 3rd edition. It makes 2 stand out a bit. If you've never played them then I think they are worth it. Just don't expect Baldur's Gate.
Ok many thanks