So many intricacies to this game and the ways it can be played, the fact you can try and balance out the damage you're taking to heal etc. is awesome.  I almost want to do a challenge run to see how long I can last by just slamming into enemies to heal.

As for actual feedback though:

• Ammo, it almost never seems to show up in actual gameplay, and I'm still unsure as to what it changes it or what impact the specific number has on the gameplay. Since as long as I wasn't missing enemies I generally never seemed to run out which made it a unnoticed mechanic mostly for me.
• The tutorial/controls on the menu were pretty concise, the only issue I had was that M2 was called "Heal ball" which was slightly confusing.  I ended up figuring out how to kill things based off how the player dies. Then went from there.  Maybe changing them to "Positive Ball"(or shot) and "Negative Ball"(or shot) would make it clearer?  Then just making the positive and negative symbols on the enemies a little more prominent would be helpful.
• (Suggestion) Maybe having the "health" of the enemies depending on their charge impact some of their stats?  Speed etc. so a positive enemy with less charge moves slower and fires slower but will take longer to kill due to their charge.  Whereas the more charge they have the easier they are to kill and the more dangerous.

I've gotta say this is one of the most interesting and unique games I've played from this jam, the way you can tackle the enemies a number of different ways (of which my favorite is slamming into them to balance my charge) leads to some interesting gameplay that mixes it up quite a bit.

my brain is hurting

perfect idea