What discourages buying a new adventure game for me is:
- first person (exception - CSI games - I love them all),
- keyboard control system (exception - Grim Fandango),
- fighting etc - (apart from Dreamfall),
- Polish voice overs without an option to choose English ones - no exceptions here.
That's basically it - all the other games I like to own and put them together on my shelf in their coulourful boxes. I just sometimes await till some of them get cheaper, especially if the reviews are bad