Right - So first off, you're a fairly new member - Welcome! Also, to make the Youtube video appear, only use the last part of the URL in the brackets.
https://www.youtube.com/watch?v=0IwZsHWKEV8
Onto your reel -
First thing is first - iMovie default transitions and backgrounds - stay away from them if you can - In fact, considering you've been making films for three years, I'd consider graduating from the program entirely. For people who have used iMovie, which is a great many, a project gives off an amateurish aura when the iMovie templates are present.
Your most impressive clips are the animated effects - Stuff like the box being thrown around and the guy getting attacked by drones. That's good, and should be part of the reel. However, it seems a lot of the reel is spent on random shots of people walking to different places, people sitting and talking, etc - that doesn't give us much of anything. That's about four fifths of your reel. Remember, a reel is no different than a trailer for a film - It's supposed to make you look shiny and wonderful - which is why you only want to use the visual stuff. If you decide to use things like people walking, talking, etc... then keep the audio in the mix to give that section of the reel purpose.
My suggestion to you would to focus your future endeavors on editing and camerawork. You don't need a fantastic camera, but a lot of the stuff is a bit shaky, the colors are difficult, etc. It shows you have a wealth of ideas - and you have people executing them with you. But, I think more TLC during the process will give you a much better product.
