Hello
First off I really enjoyed this short. You guys obviously put the effort in and it really shows. Since you asked for constructive criticism here you go.
Harsh lighting
In the opening shot there is alot of obvious non natural lighting. Im not sure if you used or have access to a lighting kit but I noticed in the interior shots alot of harsh yellow light. This caused a few scenes to go out of focus and visible camera noise creeped into the shot. You can solve this by buying a LED lighting kit that gives off at least 500kw of light.
Actors
I never nitpick amateur films for acting becasue being an amateur myself you have to expect to have iffy acting. But overall your cast was great. My only issue I saw was that I noticed a few of the girls were trying to hold back smiles/laughter and some smirks got into the shots.
Camera Work
You had some great angles that set up the tension really well. My suggestion is to limit the amount of handheld though. When you go hand held you cant help but have a slight tremble. Combine the tremble with harsh yellow light and it creates video noise. You can eliminate alot of the tremble by mounting your camera on a tripod and holding the tripod to shoot.
Focus
There were a few out of focus shots that Im not sure were intentional. Closeups of the conversations as well as some walking shots were fuzzy.
Minor Goofs that everyone does
I noticed the camera man/woman in some reflections. Not a big deal but can be annoying when you notice it while editing. In my last one I noticed a few shots of my lighting kit
So thats my feedback. I am in no way trying to attack your short or be a jerk...I just hate it when I ask for feedback and everyone just says "thats cool!"...you cant get better without trial and error.
Anyway, I loved that after credits scene and I subbed to your channel. I hope some of these tips help.