Lack of good storyline.

It's entirely possible that sending the audience out feeling lousy was intentional

The plot isn't so bad, but the pace of storytelling is too slow which makes people bored. Certain moments are so obvious and unnecessary for the main plot. I would've fast-forwarded those moments if it was an online streaming. The ending looks like implying a sequel, not sure if this movie will get one

Yes, absolutely, there is fun to be had, as well as many, many things to go boom, all amid an atmospheric urban jungle.