Halo has been a flagship title for Xbox consoles for more than a decade, it has spawned numerous titles and spin-offs, but apparently animation movie is not a priority. The CGI is incredibly stiff and design is equally lackluster, there is barely any shred of production value of the game here. This will no doubt disappoint the fans while probably won't attract any casual movie viewers.
It tells the story of John / Master Chief, the main protagonist as he goes through his training and childhood. He is not the easiest character to transition to cinema as he's a silent protagonist on the game. The animation delivers his story by narrations from other characters, while Joh himself is pretty one dimensional. His interactions are mostly military oriented, leaving little room to expand.
To make matter worse, it utilizes the same formulaic sequences like those in Universal Soldier films. Also, characters' facial expressions are extremely bland. Animation can barely produce any quality equivalent to today's game cutscenes. It's just plain rigid motion and uninteresting setting for one hour, and that short runtime will not amount much in term of narrative anyway.
The low quality visual will most likely upset gamers, and it's certainly not the introduction story Halo would like to represent the franchise on animation genre.