TLDR: First half is absolutely awful, second half is alright. Bonus levels suck. Stick to the first DLC.
I really wanted to love this DLC, especially considering how much I loved the first DLC and the base game but I just... can't. The first half of this DLC is awful. It's annoying, frustrating, and not at all fun. Each puzzle has five different convoluted solutions to them, taking away any satisfaction of finding a solution. You spend fifteen minutes solving the puzzle only to get to the end and realize there's four other solutions. Fun.... It takes away a lot of the joy of the original game and no longer makes it rewarding for the player. It feels more like a chore. Adding on to this, a lot of the puzzles are VERY specific on their solution. For example, the ink bottle level has two solutions, one which is lining up the labels. If you don't line them up EXACTLY the way the game wants you to, it doesn't count, leading you to question if this is even a solution at all. I know this sounds like I'm exaggerating, but read any reviews and that'll recount the same. It's annoying as hell...
Now I do say only the first half of the DLC is awful, because the second half is surprisely okay. There are still multiple solutions, but they're not frustrating to find and it's not five solutions per puzzle, only two or three. I find these more satisfying and more akin to the base game and the previous DLC. If I was judging this DLC only by it's second half I would give it a thumbs up. Unfortunately, the first half of the game still exists and the bonus levels, which are also bad.
The bonus levels suffer from the same problems as the first half of the game, only you have to 'unlock' them by getting enough stars. To be fair, not ALL of them are awful, just the majority of them. I really like this game and the previous DLC, so I hope the developers take the feedback of this DLC into account when/if designing another DLC. More solutions doesn't equal more fun, especially when they're convoluted....