One neat thing about Mary Skelter 2 is that the characters join you in roughly opposite the order they joined you in the first game. This is something I've seen in other games that bring back the old cast (such as Dungeon Travelers 2-2), and it's really nice because you get to spend more time with the characters that you had the least amount of time with before. For example, Hameln isn't an optional secret final character in this entry - she's the first blood maiden who joins after the two new characters!
Another interesting mechanic is blood farming - you can plant blood crystals inside dungeons, and as time progresses, they will bloom into equipment that you can collect. This is how you get the most powerful gear in this game. It was an interesting idea, but I felt pretty neutral about it, since it involves a lot of button spamming to plant and 'water' (with blood!) the crystals, but you can get some really powerful gear from it if you're patient and lucky.
First, I picked Fear difficulty without hesitation. In the first Mary Skelter, I felt like Fear was well balanced for most of the game, and I was able to keep pressing forward in each new dungeon with my team that specialized in spilling lots of marchen blood to restore my HP/SP. I found that this was just not possible in Mary Skelter 2's Fear mode. Even when specializing my blood maidens to hit enemy elemental weakpoints and/or job change to the blood-specialized classes, the small-fry enemies are just too tanky, and too stingy about spilling blood. Even when I managed to get the blood maidens into genocide mode, their genocide skills were weak and they couldn't destroy the enemies with enough force to send blood flying everywhere like last game, which used to help restore lost SP and keep up the pace. A few battles into any dungeon on Fear mode in the first half of MS2 and your characters are just out of SP, you're dry and you have a couple options, neither of them very fun:
1. You can install a bunch of +exp effects in a previous already-cleared dungeon and go farm much weaker enemies to level up and get gear.
2. You can just run away from all small-fry battles and rely on cheesy strategies to bring down bosses.
I did a mixture of both. Almost all the bosses are vulnerable to poison, even if it's a very low chance to hit, each tick still hits them for around 10% of their overall HP, so if you're patient you can just build all your characters to maximize defense and just rely on poison to win most of the time. Speaking of 'building for defense', all the job choices from the first Mary Skelter return in Mary Skelter 2, but enemies hit so hard that it felt hopeless to use anything but the Blood jobs that have high HP and defense. Nothing else matters if you die in one hit, after all.
I saw in Patches 1.03 and 1.04 that the game was patched to make magic skills more powerful. It was too late for me at that point, but I hope they were made a whole lot more powerful, like in the first game where sometimes they would pay for themselves in SP recovery from blood splatter. The problem of SP consumption is alleviated by the second half of the game anyway, once you have Snow White in your party to lick for SP.
Basically, I didn't have fun with the actual gameplay due to mechanic balancing on Fear difficulty. I highly recommend that you check how things feel on the latest balance patches, and if you're not having fun on Fear, turn it down to Normal difficulty. There's no reward besides frustration for sticking with it if things are still as bad as they were when I played in 1.01/1.02. I wish I had turned it down to Normal earlier instead of letting my pride hold me back for so long.
I really liked seeing how the alternate prologue altered the fate of some characters in this game, and how they dealt with it. They did a good job of making you believe that 'this is something that character would do if something different happened in the past', which is the whole setup here.
I also liked the increased spotlight on the characters from the tie-in novel in the first game (Mamoru, Hikari & co.). I think a lot of players were probably confused by them in the first game without context from the tie-in novel, but this time around they're an integral part of the story from the beginning. They're a fun bunch and I enjoyed their interactions with the party.
I liked how Tsuu and Mermaid were treated by the other characters. There's plenty of fanservice in this Compile Heart game, but very little of the 'b-b-but we're both girls!' old tired yuri tropes. The only character who is even a little confused about Tsuu and Mermaid being a couple is Gretel, and Gretel's not exactly a paragon of tactfulness in the first place, so it fits.
I got tired of the skits that just expanded on the quirks of the original blood maidens again, and also of the whole repetitive mini-skit formula of 'someone says something that causes a misunderstanding' -> 'someone says some fluffy happy slogan about friendship and trust or something' -> 'everyone makes up and learns a valuable lesson'. To be fair, this was a formula done to death in the first game too, but it really gets tiring the 7th or 8th time around.