I had a go with it and made it to the Boss.
Here is some Feedback:
-Jumping was a bit akward, when Players Y is increased (jumping)
you increase it by a nice curve, but when falling it Looks like you decremented Y by a constant value. I would love to see a curved ascend and descent of the Player.
-Graphics: sprites looked nice and where smoothly animated,
the only flaw I could spot is that Max´s cape will spin around wildly when he is resetted after death. ( Seems like the way Max is resetted should also update the saved last X and Y Values for calculating the cape, to the value he is resetted to. Nice Mercury looking water shader btw.
-Collision: Sliding collision with walls and the Level map in General works great, but when colliding with enemys there where some things I would improve:
-I lost two Energy bars while colliding with one of the Boss bullets while Standing perfectly still, easily fixable by deleting the bullet when it hits something.
-Make the Player a short period invulnerable when he is hit could also remove the Problem above and also the game would be a bit more forgiving. ( If such a timer already exists make it a bit longer, also add the ability to walk past enemys if the Player is invulnerable )
-At the very last I spotted a clipping error:
Looks like it is a set object transparency Problem.
Edit turns out this was intentional , Image removed to Keep thread clean.
I enjoyed the game so far, but the first two wall Spikes where a pain which took me 7 tries to get past them.
I like the way the camera zooms in when Max launches an attack,
also you nailed down the whole Alien Invasion theme pretty well.
Furthermore your idea for the first Boss is simple and effective ( i think you will Need to hit him from behind ),
perfect for a first time Boss.
Also the trail behind max when dashing, is kinda nice, maybe make it a bit more visible.
Tried it all while using a 360 Controller.
Edit: Image link