What felt like one of the main issues from a difficulty perspective was that enemies are in a weird middle area. They are too tanky for you to just be able to rely on passive clear with light damage entirely. But there's too many spawning for you to rely on your turret damage. This lead to just taking random unavoidable trickle damage from getting a single hit here and there early. Which would have just lead to a slow death to attrition. But the single point in regen gives significantly more regen than the amount of trickle damage you take. Meaning that the second you get regen, you basically can't die. Thus completely removing any actual difficulty.

Basically it feels like if you want the more tanky enemies, something needs to be done to make them reach you slower/spawn slower. Otherwise turret damage just isn't viable ever. Alternatively if you want it to be more screen clear focused. Like most survivor-likes. Then health would need to be in the area of bullets oneshotting, as long as you upgrade them along with enemy hp scaling, and more enemies. But again, probably slower moving/different pattern ones. If you take that approach you'd need to tune down light damage a lot though. idk, like I said. I like the light mechanic. But it does make for some difficult balancing issues to solve due to just how much screen coverage it gives "for free".