The starting section of DD was fairly heavy on the hack and slash, but I found there were enough quests in Aleroth for the demo to show the potential of the full game. When I got to the two skeletons in the catacombs having a conversation, the game really became a must buy.

Playing the demo, I was struck by how much better the game was than Diablo II, with similar controls, but with actual quests and dialog, humour, etc.
Apparently in the demo you could quicksave at the end message and then quickload to continue playing, and see a little more of Rivellon (some opponents were invisible and structures missing, since the associated graphics were not included).