Gantz

After trying to rescue a man on the subway tracks, two teens wake up in a room dominated by a mysterious black sphere that sends them to hunt down and kill aliens hiding on Earth.

Gantz is a 2011 drama mystery movie directed by Shinsuke Satô, starring Kazunari Ninomiya, Ken'ichi Matsuyama, Kanata Hongô. It holds an IMDb rating of 6.4/10 from 8,758 votes and runs 2h 10m.