There was an art area, a 'medical' area and an 'inventions' area. We couldn't get to the tower (under construction) or the changing exhibit area (also under construction). We did, though, spend around 2 hours here. The kids probably would have stayed longer except that a)the museum was closing not long after we left and b)I didn't want to wait too late before heading home.
All in all, the day was an excellent adventure. Thanks to GCA for doing a trip to the Aquarium, giving us the excuse to explore elsewhere too.