I was quite a fan of this game when it came out in jap so I've been eagerly waiting for the translation for a while. Miraculously it isn't as unreadable as the dev's last game's official translation! So why do I like this one so much? I'll warn you now, if you don't like NTR then you probably want to give this a miss, there is a pure route but it's only worth playing if you really like ASMR stuff or like the heroine enough to play through just for the couple of scenes you'll get.
The game starts with an adventurer, the PC, and his cute contracted devil Ria travelling the world. They happen upon a much higher level adventurer who goads Ria into making a bet with him. If you lose he becomes Ria's new contractor, you win and you get his sweet swag. Pretty simple right? Well he's going to do his best to cheat and get to Ria before the competition finishes. The story is very bare bones, but functional. It's also fairly linear, although there are 4 different endings to get depending on your choices you'll mostly be getting the same scenes until the end. Ria is a great heroine though, she cares about the protagonist and enjoys her time travelling with him, and is routing for you to win. But she is a devil, and if you lose she is going to leave you!
The gameplay is mostly the standard RPGmaker afair, with an awful lot of grinding. The hidden NTR aspect is quite fun, though there's not enough scenes to find and there's not much in the way of secrets to locate (no lewd toy littered room to find after a scene for example). There is a cuckold pro wizard's lewd diary to collect, but it's kinda meh. There are also sex stats, which are a must for this kind of game, but they are fairly simple.
So what does this game have? A good number of great h-scenes with fantastic art, that's what! There's a decent number and some of them are really lewd and creative, if you like NTR, especially hidden/mystery NTR then there's a lot to like here. Ria is also a 10/10 heroine, the exact right amounts of cute and erotic, though that's just in my books. There's also ASMR content, though the voice is obviously still japanese the text is translated if you like that sort of stuff.
All in all, a meh game, a great NTR game with a great heroine. If you like NTR then give it a go, if you like ASMR have a look, if you like neither, probably give this one a skip.