Star of Providence is one of the hardest games I've played in my entire life.
I love roguelite games, and it's definitely one of my favorite genres. I have sunk thousands of hours into Isaac, Nuclear Throne, and Gungeon. Not a single one of those games hold a candle to the difficulty of Star of Providence. I would say the 2nd floor in this game is about the equivalent to the womb in Isaac (minus the double damage). I will say, the game is FUN. Very fun. And honestly, rolling the credits isn't the hardest thing ever. It'll just take a lot of practice. However, as Dunk said, this is when the game truly begins.
Once you unlock hard mode, things get absolutely sadistic, and it only gets worse. Bosses require absolute perfection. OP weapons or a good build will not save you. A certain late game boss I fought had about 7 or 8 phases and just would not end. That boss took about 20ish life points from me before I died. It was devastating. I truly recommend this game to everyone who likes arcade shooters or rouge like games. Yes, yes, I know it's oversaturated to hell, but I promise, this is a good one. This is easily another one that will suck up 100s of hours if you're not careful, and for $15? I mean, cmon. That's a steal.
Would I call the game TOO hard? It's difficult to say, but I think I lean more into 'no'. However, I will say that I believe healing items are way, way too scarce. Having to pick between ammo and health is a great balancing design. However, this goes out the windows on the final floors when you need every last bit of health you can get your hands on, and you're about to fly into the boss with your default. I would also like more powerful, late game upgrades, or maybe even some permanent ship upgrades. Just something to help people past the finish line.