This review is mainly for people who, like me, don't know anything about any Fate series or games.
First off; I'm about halfway through the game. Should my opinion change at the end, I will edit this review.
*EDIT:* Finished the game. Final thoughts at the bottom.

You know those games where your choices don't matter?
Well, here, winning doesn't matter.
50% is 'fight boss -> win -> boss runs away.'
50% is 'fight boss -> win -> you run away.'
Lorewise, you are weak. And so far, you stay weak. Even though you win every battle. Wins don't matter.
You could split the planet in two with one strike and everyone, including you, would be talking about how weak you are.

Also, you might catch my drift when I say most of the dialogue (and there is a LOT of dialogue) is this:
"Oh! Of course!"
"What?"
"Ah.. It's nothing."

I finished 50% of the game and I STILL get tutorials. It doesn't let you off the leash, at all.

Before buying it, I read a review that said you can play mulltiple "servants." If that guy was a valet attendant, he would probably tell you he's driving a ferrari.
You can play SOME servants, SOMETIMES, for a couple seconds. Then you have to fill a gauge again.
They have cool attacks. But you have to fill a gauge.
You and the servants have something similar to ultimates, but you have to fill a gauge.
At least you can use cool magic. If you have the gems. Feels like a gauge, anyway.

The exploration WOULD be good, if you could explore the maps the first time you enter them.
The story WOULD be good, if it would progress at some point.
The dialogue WOULD be good, if they would get to the point sometimes.
The protagonist WOULD be cool, if the story wouldn't portrait him as the weakest wuss ever.

To summarize:
Overall, this game is incredibly frustrating. And I wish I could love it, because the fighting and the essence of the story are really good and fun. But everything around the core just spoils it.
It's like sushi dipped in ♥♥♥♥. Love sushi, but the ♥♥♥♥ ruins it. I know, high standards, right?

Again, a fan of the Fate series might have a totally different experience. And people who play novel games. If you're one of those, go buy, I guess? If not, wait for a fat discount.

*EDIT:*
Finished the game. It gets (a bit) better near the end. The last quarter, I'd say. My initial thoughts and recommendation are unchanged, though.

you can pet the cat when you turn into a pig so yes.

good game a bit slow in the at start