Creatively speaking this is excellent, it’s by far one of the better ideas I’ve seen for this clip. The scenario works very well, and I like the acting choices.
It is too long though, yes, and by quite a bit! My suggestion would have been to open with the undercover cop’s gun already drawn, and drop the whole pretext for the situation i.e. start from the dialogue around the 40 second mark. The idea is strong enough to carry from there without any explanation. Drop the filler, keep the killer.
There is also a rather complicated camera move right at the end (0:55 - 0:58) which I personally would have left out. I think this could have been staged in a much more direct way and still have had the same effect (e.g. Simply hide Cop #2 behind the wall, lead with his gun and hav him spring out from behind it).
Anyway, these points are always up for debate, as there are loads of ways to direct a short.
Technically, I would have said that this is too floaty rather than too stiff. The major problem is that the keys and breakdowns haven’t been properly developed, so there is no cushioning, drag or overlap, which means no texture or pacing. Again, personally speaking I would have ditched the physics, hair, lighting etc and just concentrated on the animation. 2 days isn’t much, so I would have spent that getting the blocking right, even if it meant not completing.
The handling of weight could also use some work. The walk at the beginning looks rather unnatural, as the hips and the body don’t seem to be working together.
My advice from here would be to go back and practice some basics, do a few bouncing ball exercises, walkcycles, lifting exercises etc. Think about weight distribution and balance, lines of action, arcs, and focus on establishing your keys and breakdowns. It’s also better to do a whole bunch of short (less than 10 sec) clips than struggle with a minute long monster.
Hope this helps, and keep it up.