Honestly if the developer turned off permadeath by default and made it optional, I think they would see MUCH more commercial success with this game. But 99% of the reasons I didn't like it ended up being because of permadeath.
Combat feels like an absolute dumpster fire. You'll throw one projectile that bounces 6 times off every object in the room and then something explodes and insta-kills your character. That happens all the time. That comes off as "hahaha so funny and quirky" when you're playing duck game. Here, it kills the character you've spent 5 missions leveling and it's not as fun.
Enemies have effects that you won't have time to understand and chaos happens all the time because of it. You thought you could disable this guy by jumping on him? No, this guy actually does damage when you jump on him. You thought you could hit this guy with a melee weapon to kill him? Nope, this guy reflects it back to you.
Then there's Spelunky level traps EVERYWHERE. You'll jump up and get hit by a wall arrow about a million times in this game. Again, if the only consequence is "I lost the mission and now have to heal that character for a long time before I get to play him again," then I think the majority of gamers will find that fair. But the fact that it is plainly punishing you for game design that is wacky, uncontrollable, and chaotic is so purely insane. It turns me off the game so bad. If you're going to have hardcore options, the game needs to be consistent and predictable.
And for everybody that's inevitably going to say "skill issue," it's really not about that. It's a poor design choice. I've beaten every Soulsborne on the market and loved every second of it. The punishments when wacky crazy stuff happens in those games are fair. It doesn't delete my character and make me start over.
Also the UI is unfortunately just as wacky and unpredictable. Did you just spend 5 minutes meticulously assigning everybody to their best role in your base? Awesome. I'm sure you won't accidentally press "Optimize" while trying to lock a character. But if you do, we'll immediately blow all your assignments away without any confirmation window or anything.