I've watched Mekakucity Actors back in 2015 and I liked it. I gave it a 7/10.
This short film is a waste of 20 minutes that I will try to help you avoid.
Animation:
1) When there's no "camera" movement, everything is okay. Not good but okay. However, when it simulates movement, it fails spectacular at it. It looks horrible.
Sound:
1) the soundtrack is nice
2) the seiyuus are the same and they're perfect at what they do
Story:
1) Stuff happens at a mall and there's no chance to get immersed and enjoy the characters or the action because the visuals are terrible and not a single bad guy acts in a believable way, even if they're under the influence of another person.
Stay away, don't bothter with this film. Go watch Mekakucity Actors if you haven't already and don't let those memories get stained by this poor excuse of a movie. 3/10