Metal Gear Solid had one heck of a storyline! It always left you on the edge of your seat begging for more. The plot could suddenly flip over when you discovered that an old ally has just shown themselves to be a traitor! MGS2 has an even more complicated story and it's not even clear who the arch-enemy is! Maybe this isn't a good thing, but it just proves how engrosing plots can become.
The music of MGS fitted the game almost perfectly. But even though it sounded great to the game, it was very... unnatural. Becuase MGS was a big success, Konami had a bigger budget for their next game so more money could be devoted to the soundtrack. Hence the orchestras they used and the famous composer they hired: Harry Gregson-Williams. The music in MGS2 is absolutely stunning and turns the game more into a movie! It's hard to beat music so good as that used in MGS2.
Now here's the biggest difference... graphics! MGS2 not only has much better graphics than MGS, but it has better graphics than most other PS2 games! You can see every last detail and it's goodbye to blurred eyes and arms that look like they could be pulled off... Did anyone else notice that? MGS had very... unique... graphics and were very good as far as PlayStation standards went, but MGS2 had some of the best for the PlayStation 2!
MGS2 has a much wider range of moves that you can get the playable character to pull off. For example, rolling, hanging from gantries, peeking round a wall, creating diversions with magazines and books, shooting in first-person and loads more... The ways you can complete MGS2 are almost endless!