Looks really good. One thing though. Like so many other new platformers out there this seems to suffer from floaty character movement decease by the look of the trailer. The character moves without any weight. So I would strongly recommend to make the character jump and fall faster. Also by adding acceleration to falls it makes jumps from higher heights feel a lot tighter.
Quick example of what I mean:
http://frozendev.com/examples/floatyVtight/index.html
This example has far from perfect controls but I hope you understand what I mean. When I jump over an enemy projectile for example I don't want to float around in the air like I'm on the moon, no I want to land quickly on the ground again and continue the action
The graphics and bosses look epic so it would be a shame if floaty controls broke the illusion. I usually don't put this much time in my feedback but I see potential in your game so I had to But with that being said I wish you the best of luck and the game looks awesome!
And I voted yes