This is a very cool game concept, I have only played through a few of the levels completely at this point but I do feel like this might be one I will come back to and play further in my downtime.  I am an avid fan of the Megaman X collection so I was feeling right at home with this gameplay style.  I found the mechanics engaging and easy to understand but I do have a lot of playtime on this type of game and that my have made it easier for me to pick up, I thought the exposition explained things pretty well but my perspective may have been skewed by that.   

Gameplay and controls felt pretty good, I generally prefer to control my characters with the D-pad in 2d sidescroller games but the joystick control was not bad.  I really liked that traditional style platforming and shooting controls.  I am also interested to see what you do with the movement upgrades as the game progresses, I made it to the double jump upgrade and I was pretty excited to see some of the level design stuff it looked like you were planning with that mechanic.  

I had fun and found it engaging.  There are enough upgrades and interesting stuff to find to drive the game forward and keep players attention.  The interface was neat and user friendly as well, nothing major holding you back there.  

I think I may have found a minor bug on world 1-1, in the cave area where you find the first upgrade.  I missed the platform on my jump and ran out the exit without grabbing the upgrade.  When I went back into the cave through the exit door I could not see my character and it seemed like I might have been soft locked in some way.  I reset the level and played through the second time with no issues but it might have been something weird going on (or possibly I was just stuck on something in the doorway I'm not entirely sure).  

Very cool looking game though, and the style is very consistent. I always appreciate art direction in indie games.  The attention to detail is for sure doing you favors here!  Excited to see more.