This game was incredibly fun! I replayed it many times and was on the edge of my seat for most of it! The music was great, the action was phenomenal and the changing color pallet was a nice touch. Getting the piercing shot and lining up a line of enemies in slow motion felt truly awesome. I am impressed you made a game like this in just a week.
If you wanted to improve, finding a different way to display the powerup times could be nice. I was too focused on the player to ever check and see how much time I had left. Maybe do something like the shield with all of them and just have it fade away over time.
Overall fantastic game!