I couldn't actually finish this game because of how really unpleasant it is, so I was really impressed by it. Given the way the narrative was going, most games I would have tapped out wayyy earlier. However, the strong narrative and characters kept me around until floor 18, when I just couldn't keep going with it anymore. I don't think I'll ever actually finish this game, but I wanted to note how strongly effective it was. I can't say if it stayed good until the end, but I just had to leave a comment with how strong it was for the parts I saw. Even down to the combat, the way the character's level-up skills almost always were good for one character and bad for the other really showed just how much they loathed each other. That, especially with the ways the unlocked stories unfolded over time, and things that originally appeared one way (like, say, some of the disappearances from people trying to reach the bottom of the slime dungeon) were revealed to be not as they originally seemed. I would absolutely love to see the end of this, I just don't think I can actually finish playing through it.
Additionally, the combat is really good. The combination of skills (in which so many of them have terrible drawbacks because of How Much They Hate Each Other), the way guns were implemented, I was legitimately surprised by how it managed to not get really boring, even when you went through every fight.
Long story short, even though I couldn't bring myself to finish the game, I was really impressed by it.