You’ll want to return to levels through Free Play — open the map menu and scroll left to reach the level select. Here, you can replay any level in the story with all your current characters unlocked. You’ll want to unlock as many characters as you can first.
How do you get the mystery bag in Lego Incredibles?
Finish all of the Crimewaves (10 per every city district in a linear order). Complete all of the Challenges (20 in total: 10 per every district and another 10, scattered all around Municiberg). Unlocking and opening 93 Mystery Bags, which you receive for completing other, previously mentioned objectives.
Where are all the fires in Lego Incredibles?
There are very many fires all over the city (e.g. a barn in the western part of Outer Municiberg, and in the south, in the Urbem Heights district, just below the highway.