I just don't like clunky fights with Zombies that keep coming and coming, not to mention the bad-breath-dinosaur creatures. It wasn't a game killer, but still annoyed the hell out of me.I often got lost too, with no hints where to continue....very frustrating. Thief 2 had better (and bigger) missions that suggested the player to use his tools more intensely. It also made better use of in-game hints like conversations and such. I felt more like playing a Thief rather than a mere rogue. Apart from the first TDP mission, it became worse and worse, while Thief2 kept getting better and better. Thief 2 > Thief1.
Deal with the truth!