Short promotional OVA from 2014 that was lost media until 2023. That means it is quite obscure. It had no reviews previous to this one. That means I am obligated to write one. I'm not sure if I would call it promotional since it is an original series, not based on a manga or light novel or game. Unfortunately, it seems this instrumental, 7min, action packed trailer didn't make much of an impression on producers. Yes, it doesn't have any voices, excepct for like 4 lines right at the end. So, we don't get any background to the story (unless you read the synopsis beforewatching).

Is it good? Art and character design is decent for the time period. Good use of CGI animation, as well as traditional 2D animation. That is basically its strong point. Even though it is instrumental, music and sfx are nothing special. Not much to say other than that. I just thought it was a decent "what if".