 If you liked
Shingeki no Kyojin
|
 ...then you might like
Gunka no Baltzar
|
Both have a very rich and detailed world where the main setting is a highly militaristic country of steampunk / victorian era technology. Both titles also have massive battles where strategy and intelligent thinking is much more important than shear brute strength with a very well thought out scenarios that are both complex and rather easy to follow