Hardmode is garbage. It's pure spam, very very easily overwhelming all even the most optimal and lucky builds, with far too much overreliance in particular on spamming the most bullshit of enemies, E.G. the absurdly tanky exploding flies that explicitly require sacrificing babies to eliminate (and block spots just to rub salt in the wound) and the flying enemies that can and will fuck you with zero warning due to hiding behind enemies and being a bullshit enemy to begin with. When it's a struggle to beat the first fucking level with optimal play, you have done a shit job.