The intro was cool, but when the first shot opened up, it literally hurt my eyes with so much bright white.
There's some things the fighting itself could improve on as far as what can sell the punching. When DP is watching, they should be able to say "that looked bad" and try something different. There were numerous times where punches didn't remotely look like they connected. A simple way around this is different camera angles, and yes, that means doing the fight over and over again. Cocking back a swing or a jab, going across and past the other person will sell a better hit, with the camera behind either person. Throw in some close ups of different hits/reactions, and you will start to see your action piece together into something far more believable and gritty. "One take wonders" for entire complex fight choreographs are rarely done, unless you're jackie chan.
Another thing I saw that bothered me was the camera suddenly changed ISO in the middle of a cross fade. And I would stay away from trying to walk with the camera and throwing on stablization in post unless it is absolutely needed (such as driving with a camera in a car).
I don't mean to sound so harsh, but you remind me of what my friends and I used to do on weekends, which was attempt at making cool action movie stuff. It's fun and a great way to learn, I'm just giving you some perspective as to what I've learned trying to do the same thing that you're doing.
I'll post an example of a fight scene we made back in our senior year of high school, part of a web series we very amateurly produced.
Start at 3:09
https://www.youtube.com/watch?v=L1S9r6wE68g
