 If you liked Metropolis |  ...then you might like Steamboy |
Both are action-adventure movies involving the progress of technology and society.
I just watched Steamboy, and it reminded me of Metropolis, which I've seen years ago, before I even knew the term "anime". Now when I think about it, there are many similarities, such as the technical environment, large-scale scenes and mad scientists. School-age boy and a girl are present in both films as main characters.