My kids are 6 and 4.  However, they currently love the "Gussie" game.

They say, "My name is Gussie and I'm two years old".  And the other says, "I'm two years old and I'm named Gussie".  They're the Gussie twins!

Playing this game allows them to play baby games like crawling around on the floor, and talking in baby talk.  They love it!