Wow, the concept or low-life high-power taken to the extreme! I like how you manage your life/power. But once I realized I could “evacuate” dark energy from my body I wasn’t too worried about it and just rushed through the levels shooting randomly until I reached the boss. Maybe some incentive to get stronger shoot to actually destroy mandatory enemies (gates?) would have prevented this.
For the boss, it was pure balance finding, touching the big bullets from times to times. Clever use of mechanics/voice style of the previous game!