In their "comeback" Korean album Wonder World, the group displays a maturity in everything from recordings to looks (black and white motif a la Beyonce's Single Ladies music video).
Wonder World sports a healthy balance of styles, ranging from the typical, high-energy K-pop songs to softer ballads, and even a hip-hop track that shows some attitude (Act Cool).
Both lead single Be My Baby and G.N.O. are dance numbers meant to get people hyped. While Be My Baby slightly resembles Nobody as it dips into the retro sounds, G.N.O. (short for "girls' night out") is a party track that's been infused with the American club sound and gets people moving with its pulsing electronic beats. Girls Girls offers a good break, as it's a slower, more acoustic track. My personal favourite is Stop! as it has a highly contagious, yet ironic, hook that leaves you singing it hours after you have listened to the track.
One can't help but wonder what's next for the Wonder Girls after dominating the world. Outer space, perhaps? I'm sure they'll pick up Martian in no time, just like they did Japanese, Chinese and English.