What was a huge step up for this game was the fact that it was on a handheld console. The Animal Crossing series is based around maintaining a virtual village; this is made up of tasks like picking the weeds, nurturing friendships with fellow villagers, paying off the debt on your house, going fishing and things like that. These are all little tasks which the game encourages you to do every single day, which is so much easier to do if you're playing on a portable console. Now playing late into the night (as you need to do for some things) or finding a few minutes to play each day, is not too difficult.
What is a little sad about this game is the fact that it has a significantly smaller number holidays celebrated in the game (which had been a big part of the last game) but on the flip side, that's made up for with the ability to play with your friends. You can now visit your friend's town while they are also playing. I loved visiting other towns and looking in other people's houses. Before the Nintendo W-Fi service was discontinued, you could even visit people's towns over the internet; sadly, however, this was limited to the towns of people you knew.
Generally, though the reduced number of holidays is sad, I found that this game generally improved over the first in every way. There's now a nice little database for all of the fish and bugs you catch, you can now buy hats in order to further customise your villagers, there are several new special characters, houses can now be bigger than ever and there are extra fish and bugs to catch. It's an absolutely excellent game and one which you'll easily pour hundreds of hours into.