You can pick up many different items, but the kicker is most of them are useless. There is a place to dump useless items, but having to flip through all of the pages in your inventory and even dropping the ones you don't need can get a bit annoying. Like Shadowgate, you learn spells, although most of them are given to you right at the beginning of the game. The graphic quality has improved slightly, with a bit more detail in the pictures. The music actually isn't as good as the other two games, but it's not bad.
Some bits are annoying, others are enjoyable.
Overall, Uninvited is a worthy addition and final bookend to the trilogy. Once you've beaten it, there's little reason to go back and play it, but exploring the mansion can be fun, and the puzzles give you a good sense of reward once you figure them out.