Gantz:O

both have fantastic CGI, action, and (kind of) require no prior knowledge of the franchise before going into the movie. Gantz:O has CGI with models that are more akin towards anime (they all look like k-pop stars) whereas Kingsglaive takes a more Hollywood approach with models that are more Western. though the effects in both are definitely cinema notch 

Both anime involve humans desperately battling against hoards of aliens resulting in many gory deaths and a continuous feeling of despair.  

Both have the same feel of raw brutality  

both anime has very good CGI animation, Very epic Fight,, And Great Character Desaign,, if you search for action movie in CGi you should watch both,,  

Why do I recommend Gantz:O?Well, that is because of the action the two series present, the great character design for the antagonists and also for the psychological element they both present. They also feel similar in that they present a continues fight, that is if you take the slice of life, dramatic moments aside from Black Rock Shooter. 

Action with an element of gore is the way to describe those two anime.It takes a while for the monsters to appear in Berserk, but otherwise the two feel the same from an action standpoint.The only thing that is better in Berserk is the drama. Also both are anime movies with great CGI animation. 

CGI spectacles where our heroes face off against a seemingly endless horde of monsters. 

If what you want want is a lot of action with an element(more in Drifters) of strategy in it, than you are looking for one of those two. They differ in that one is about fighting aliens(Gantz:O) and the other is about fights between historical character with or without magical powers(Drifters).