Addictive, if not challenging.
Not really challenging, but plenty of replay value for completion fans.
We have completed it on story made, and are currently replaying it on the excellent free play mode.
I found the villain missions to be more fun than the superhero missions, with the number of excellent villains from the DC universe. There's just something about frying a little Lego man with the manic jokers hand buzzer!
The Super villain missions are unlocked after completing the main Superhero story arcs. Each arc contains a number of missions, split between vehicle missions and missions on foot.
The vehicle missions do tend to be a bit repetitive, whether it's driving a boat, car or flying a plane. You get two vehicles to toggle between, one with a tow rope, and one that can fire missiles.
Anyone familiar with the Lego Star Wars games will be able to pick the controls up instantly. I'd recommend this game to both fans of the Batman universe, and to younger gamers.