Right, spoilery stuff, so don't read if you're not interested.
For the game: Blue/green marks are shops/helpful info. Orange marks are quests - sometimes rape. Red marks are important quests/plot points supposedly, Purple marks are for dark magic advancement - almost always rape. Save before activating one, if you want to avoid rapes.
The MC is the leader/boss of a girl gang. After winning a gang fight, she dies protecting her underling from a knife hit of a defeated opponent's backstab attack. Then she gets isekai'd by a shitty king type of summoning.
The shitty king's daughter looks just like her former underling so they stay friends as MC escapes the castle.
Queue the world map where you can travel freely from location to location on a preset route, which expands as the plot advances.
Stats increase by increasing your rank and your rank increases by eating food. Supposedly you get fatter with bigger boobs, but i didn't make it that far.
Combat is first guessing which move a specific mob is vulnerable to and then spamming it for big critical damage while trying not to lose. Or just use the basic attack for average damage. The "Powerful Move" shtick is just choosing between combat erotic scene or not. Can't block it, only avoid.
Magic is kinda dumb. MC's type is darkness, but no one knows how it works because plot. Mc finally meets a shady dude later on who says she needs to get fucked first to use that magic, which is bullshit of course. You'll later find something that lets you use dark magic, but only one move because the game author was too lazy to actually map a non-rape route for magic. Or maybe it's just the bad translation that implies that, don't know.
Doesn't matter anyway because you don't need it much.
Do not the cat if you don't want to get raped. It is one of the most shittiest moves in gaming and i'm dropping a star from the review just for remembering it.
Story spoiler part:
Then again, the translation is what it is and i skipped a lot of stuff, so i'm missing the details probably.
I reached the going back home ending. Don't care if there are any others.
Visually, the style looks great. But as usual, it is marred by the superficiality of both gameplay and erotic component integration. If there is a non-erotic version, try that one instead. Otherwise just type DevilMary in the recollection screen and watch the scenes directly.