Hmm, hard to say, as there isn't much to the games that I actually dislike. This has been greatly improved from R/B/Y though, but all the caves I guess. Mt. Moon is pretty much the same as it was back in the old games, but the Rock Tunnel was so much less of a pain going through when you were actually able to see something, however it's still the thing I dislike the most about the game. What I liked the most about the game would probably be all the post-game inclusions. All the stuff they added with the Sevii isles, and the stuff you had to go through before being able to battle Mewtwo were some of the things that really helped make the game better than the originals, even though FR/LG have gotten much critique.