Making 500+ enemies wave is too much, even with a 4-handed build and a grenade launcher without reloading and explosive enemies, I don't think that PC would even handle this. any ideas how to optimize it? the number of enemies is not always a sign of difficulty....

And also any feedback

You can write here any ideas for perks, rooms, enemies etc.

Is this a roguelite with meta progression of some sort or is it more of a roguelike where you have the same start each time you die with no metaprogression?

yea