I've only just completed my first run and beat the last boss for the first time, but holy moly I absolutely will be playing more. It's extremely satisfying to get a good run going, and the game doesn't pull its punches, either. Would imagine it gets even harder with other weapons that aren't as generally reliable as the Splattershot.

I simply think it could use better floor variety, include more weapons, and have more chips to add to your palette. Plus maybe having the Spire be a few floors taller. But I should also probably keep in mind this is a DLC side-mode and not its own entire game.

Pearl and Marina's Honeymoon DLC is an A+.