Tech katanas, mechs, lasers and demons all with awesome animations and a nice linear good vs bad guy plot, does it need anything more!?
As the title suggests, GANTZ:O is a pretty good action themed animation. I read there is a bigger background to it, but even though I don't have any particular knowledge of it, the movie was still enjoyable and understandable.
Also, there are no tedious parts with long explanations since in most of the screen time there is some kind of battle taking place. The animations are all on point and eye pleasing.
All in all, if you are an animation fan then it's definitely worth a view. (lang: Japanese, subs: Eng)