It's not steampunk, if it's apocalyptic. On the other hand, apocalyptic usually means no-magic (replacing it with magic-equivalent - psyonics, computer manipulation, matter transformations, etc).
Anyway, description sounds vaguely familiar... But no, I cannot remember. Can you describe more? How game is played - top down, isometric, side, first person? What battles looks like - FF-style "standing parties hit each other", or involving battlefield with free movement? What is it _outside_ of battle - movement only, quests, world?..
__________________
|