It's not a bad rendition of a cliched idea. But, there are several areas for improvement.
- At around 1:28 when the door closes, it would be much better if it actually closed with a good ambience sound
- As mentioned previously, the plant was horrible distracting. It would be much better if it was behind the subject and possibly out of focus. As it is, I was looking at it more than the subject.
- There was a lack of suspense at the ending. Partially, this is because we know there'll be an assassination due to the convention of these stories. Secondly, the gun look more like the camera. Finally, the sound just didn't work.
I think, It would have been better if you had a low angle shot where you can see both subjects and the gun, and have the camera zoom up to the barrel. A Sudden 'Bang' sound (The Sound would have to be more realistic and less futuristic would be better. The current sound took me out of the story) and instantly black out.
Not only would it ending be a little more sudden and climatic, it would show his expertise as an assassin as it would only require one shot rather than the many shots he currently took.
But none the less, it was a good film. The grading is a good start, but I wasn't sure what you wanted to show with the grading. As for the narrative, it was like I said - cliche and conventional. What would have benefitted might be an extra 30 seconds or so to flesh out a character so we could have connected with him better.

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