An iPhone? Ah, I can't help you with that.
The only hint I've found is from
this thread. I know it says RPG Maker, but MV games are basically HTML games with a quirk.
As far as I understand, first you must install the
Offline Pages app on your phone and use your pc to extract the game.
Then you must open iTunes, go to filesharing and drag the game folder into Offline Pages.
Once the folder is transferred, open it with Offline Pages and play it (I guess you must open begin.html in Safari?).
Again, I don't own any Apple device, so I can't test this solution.
Alternatively, you can upload the game on gamcore.com and play it there lol. They already have Crystal part 1 and 2.
I just don't know if your iPhone can play all the media files included in the game (videos, webPs and so on).