It takes 3 days to get your bars full enough to do an Adventure and then unlock a new level of any of the games in the arcade. There is no other way to "unlock" things or get pics, furniture, hats, buddies (aside from codes) and music. Once you've beaten all the games that were already unlocked from the start of the game, you'll only have your chores and favor to do each day. On the third day, you can unlock a new game level. It's slow, and aside from that, there isn't a whole lot involved in the game, but it's still a bunch of fun.
It's also fun to go decorate your room with different themes. Sometimes if I'm really bored, and have nothing better to do, I'll go play a couple of my favorite games. Otherwise, I just do the chores and favor and that's it.
I think another part of the charm of the game is that every month there are new updates and new parts of the house have been opened up. Those that started the game late may not have been around when it was only the 1st and 2nd floors open. So that was another element of excitement in the game. I know I had lots of anticipation for what was on the other floors and outside.
~Vicks