Hey! I agree that the first level is far too dark. This was something I wanted to fix, but couldn't find a balance between atmosphere and visibility personally. It's unfortunate, but at least the 2nd level and further are lit brightly.
enemy telegraphing - Enemies have a blue indicator over their heads just before they attack. Unfortunately their animations don't have enough wind-up. The mech has no indicator, but the mechanic is that he always attacks predictably (whenever you are in range he instantly attacks), so I felt he did not need much telegraphing. Good to hear the feedback though! If I release a post jam enhanced edition, I'll include better attack telegraphing for enemies.