So, I like the pixel art. But I really miss some sfx and music, as well as gamepad support.
And I don't think I would have figured out the box thing at the start without seeing it in your GIF.
But aside from that it is a nice game. Good job
gamepad support (XBox) play via https://mightypixel.co.uk/abyssXbox/index.html
d-pad Left and Right
d-pad Down activate lifts etc
A: Jump
X:Shoot (when you have bullets)