The Dungeon Pets expansion does a very good job of what most expansions do; add more stuff. The more stuff including new ways to use imps that stayed at home, a black market that allows new ways to get stuff, fortune telling that allows predictions on future buyers and contest, and charms that add extra needs.
The problem with this, is that Dungeon Petz, the main game already has a lot of stuff and a lot of options. So, the expansion actually adds a lot to the problem the original game had. Explaining all the rules with it takes even longer and there are more of them to keep tract of. Because of this, some of my older siblings refuse to play with the expansion because they don’t want to deal with even more rules. My eldest brother though likes the expansion though because it allows everyone to get a pet first turn, because he considers not getting a pet the first turn to be a major disadvantage.
So, this expansion tends to be very hit or miss. I personally don’t like it very much, because I consider it to be just a few too many things to keep track of, but I still enjoyed it.
If you have never played the original game, do not tree it with the expansion first. It is too much to learn at once for the vast majority of people. But if you already know and like the original game, and don’t mind the more rules, then it does offer some new strategies and ways of getting things that you may enjoy.