Negadon: The Monster from Mars

In an alternate 1925, rapid overpopulation pushes humanity to initiate ambitious terraforming operations on Mars. When an automated Japanese spacecraft returning from the red planet crashes into downtown Tokyo, it releases Negadon, a colossal extraterrestrial behemoth encased in indestructible rocky armor. Conventional military missiles and artillery prove utterly useless as the rampaging kaiju incinerates suburban neighborhoods with searing heat rays. Humanity's last hope rests on Ryuichi Narasaki, a reclusive former roboticist haunted by a tragic past test accident, who reactivates his colossal drill-equipped battle machine Miroku to wage a desperate last stand.