As you have seen balancing games is hard and not everyone likes the same level of challenge, so before the 1.0 release i think the game should have at least 2 difficulties to select from (both with the hardcore option).
You’ve already shown us that it’s possible to make the game harder by having smarter enemy ai, scarcer resources and tighter gameplay mechanics, and i think that should be a good thing to separate the game on normal and hard modes (instead of only changing enemy stats as many games do badly).
That would make more people happy and require less work on adjusting difficulty upwards and then downwards each time you release content. You can’t have the perfect balance for everyone.
A little feedback while i’m here, the first boss is now too easy. He has barely any health and dies immediatly, and that’s stated both by challenge enjoyers and casuals.