One of the best RPG Maker games that I've played in terms of gameplay. Beat the first Black Souls' Ending C before this one, or else you won't fully appreciate this one.
Combat
This game mainly sticks to default RPG Maker mechanics, but it uses them to its fullest extent. Your combat strategy can involve winning by stacking damage over time, countering everything, critting with weapons that you can't crit with, becoming an immortal wizard with zero HP, dumping defense to spam nukes on turn 1, gaining enough defense to tank everything but be unable to heal, etc.
The freedom of choice makes gaining new equipment very enjoyable: "How can I use this new toy to pleasure myself?" Ring that drastically increases all stats but gives -20% HP regen? Tricky to use. Pair it with the mace that gives 20% HP regen? Aha, now we're cooking.
Special shoutout to the God's Odd Fish enemy for forcing me to adopt the most ridiculous combat strategy ever of constantly being at 0 HP and taking three actions per turn to whittle down its health at the pace of a lethargic snail. It became my #1 favorite RPG Maker fight ever despite dying a ton.
Overworld
I don't recall seeing any areas with default tilesets, although some events (characters' sprites) use defaults.
The huge overworld feels enjoyable to explore, with secrets hidden everywhere. Try to go without a guide for as long as you can. The sheer amount of running around gets a bit tiring, so I heavily suggest that you talk to a certain character as noted in the hints text file.
I didn't know about the game's coolest feature until discovering it by accident halfway through my playthrough, and I want others to have the same unspoiled experience. From a dev's perspective, it's a ton of work to add, meriting another run of all the game's areas to check out.
Story
A sequel to a game about fairy tales unsurprisingly also contains heavy amounts of references to literary works, this time being the Alice duology and the real-life circumstances leading to its creation.
Black Souls II throws you in Wonderland, and unless you're nerdy- sorry, scholarly- enough to recall obscure tidbits such as Charles Dodgson's sus photography habits, you might find the story somewhat difficult to follow. It's Wonderland, so did you expect much common sense?
The characters have emotions. Feel free to treat them like your BFF or condemn them to a living hell. I felt happy to see them happy, and the game does its best to make you feel sad when they inevitably die/get betrayed/get imprisoned/get eaten/drown/die by childbirth/get murdered/get cuckolded because of the player's curiosity.
You'll encounter psychological horror and drugs, like every other modern Alice game nowadays. It might frighten an older child, but it's tame enough for the people playing this.
Getting to the end of the story was slightly more difficult than I would have liked. It's a common issue for RPG Maker games to have difficult ending conditions.
Music & Sound Design
Overworld music is great. Combat music is nothing but bangers. They mainly use free songs to the best of my knowledge, but that doesn't mean that they are bad.
Surprisingly, the dev paid careful attention to sound design, resulting in combat sounding brutal with screaming and brutal crits, creepy battle intro and outros, different footstep sounds, and a giant fish roaring as it blows you to smithereens for the umpteenth time. This isn't easy to do, so major props.
Graphics
Most enemies have their own graphic, and each area has its own tileset. You won't get bored running through each area, and there is a proper lighting system.
Animations suffer the most, with many of them stock.
The H-scenes are well drawn.
Tl;dr
Great 20+ hour journey to find my mommy MILF Alice while getting my ass beaten for a couple of hours by an overgrown tuna.