It's an RPG Maker game, so if you can play one of those, you can play this. Anyway, here's some more screenshots from the game. I decided to censor them to keep them within the forum rules.
First off, on the dark path, the first tie-up happens right away when you kidnap Donna by convincing her you're a spy. Quite a bit of binding time before the inevitable sex.
Second, the dark route to recruit Samanth is kindapping her instead of seducing her. I went with this shot since it's just a bare butt.
If you decide to let the girls fight out their differences, the scene ends with both of them cuffed.
And the last dark exclusive for now is if you recruit Sarah via kidnapping. Probably one of the most elaborate bindings thus far.
The thief Noemi gets tied up twice. The first time is when you have to free her from jail.
She gets tied up again in an optional scene when your party catches her trying some impromptu revenge and you have to set her straight.
At one point, you free a warrior from a mind control spell and have to tie her up to get her under control. Which involves sex.
In one of the optional quests to recruit an isolated tribe to your cause, you have to convince one of the warriors, who's been trying her darndest to prove you aren't their mythic savior. She went too far and got tied up for it.

"The quality of your lives depends on what you make of them! The only limits to adventure are the limits of your imagination!" — Scrooge McDuck, The Richest Duck in the World