I honestly love this game. It has great controls, a fantastic "learn as you play" tutorial, easy to understand mechanics, and a double jump. :D
I love that it makes you feel like every decision, indecision, and action matters. The fact that your energy is constantly draining, and you have to fight to get more, turns it into a frantic, search and destroy, almost speedrunner type game. A lot of fun! :)

Great tutorial, smooth controls, I would copy+paste the above review, because it's so accurate. I also like the graphics, as it is very neat

Basic game mechanics are done very well and work fine, there could be few improvements though
Even adding a simple sounds on hit from freesound.org would give it a way greater feel. Enemies shouldnt damage you when they have 0 hp, just add a line of code if (health > 0) when enemy damages you. Also increase gravity for enemies when they fall. In addition shooting is useless right now, increase its range otherwise it does 1/10 damage of what normal hit does but has nearly exact same range, this will allow to do small damage but at same time avoid trigger from enemy.

Is this done on Game maker ? If so switch to Unity one day that will allow you to expand on your skills in exponential progression.
For example:
You can also instantiate particles and shake the camera (brackeys has tutorial on that) when you hit the enemy or enemy hits you to emphasize on that. Also if you want to leave blood stains or something use sprite masks (Blackthornprod has tutorial on game feel and the sprite masks in general that will help a lot )
Discarding anything the lacks in the game, it has been done well within what the "Basics" of it and feels very smooth, I assume you are yet starting out and you said its your first LD project, on that its a very well done, trying and practicing makes perfect, but you just need to acquire more knowledge from different sources.

Keep it up man!

Edit: Didn't know you have so much levels 0_o gj on that too

Overall it was a nice game, I liked the feeling of progression and contant pressure of life costs for upgrades, would i dare to upgrade?
That being said, it would have been even better if there were more things to upgrade. I reached level 15 and then the updates were the same, so maybe something like further melee reach would be nice, or other cool abilities.

Art is understandably hard to make alone for a Compo, though it was a bit hard to tell sometimes where my character was facing, so i had to guess a bit when fighting.
AI wasn't much of a challenge, as i could stay above them or below them and they wouldn't move, i could just freely hit them then.

But i love the concept though! If you continue the development and add more things while working on some sprites, i would definetly come back to the game to play again!

Quite an addictive game, despite becoming easier as the game goes on. I really like the concept of increasing your max energy when picking up a battery at max charge. The controls are smooth too.

I played the game and concept is good but there is some little things makes game annoying.
1- When i die. everything starts again.
2- Red boxes can deal damage while their health is less or equal to zero.
3- control scheme is a bit weird to remember and firing with shift triggers sticky keys afer 5 hit.

About graphics and environment. I like your platformer game with boxy design. It feels smooth moves smooth but things that i mentioned above are bit annoying. Good game!