So I ended up re-subbing for a bit to try the game out. I will immediately say I do not know how to pull a copy of this game from their website and even if I did I don't think we have the means to crack it.
It looks like the whole game was done in Unity so I'll do a quick amateur rundown comparing it to the previous version.
Art: 6/10. Slightly above their average game but it's the normal style they use. Renders are a little bit better but I wouldn't say they're extravagant. They did add more animations which was a nice bonus.
Story: 8/10. It's more interesting now with the sister introduced as it actually adds a backstory to some of the main characters which you do end up uncovering as you progress through the game, a nd of course there are more endings added.
Gameplay: 5/10. Again this is comparing it to the previous version. The gameplay is essencially the exact same so there were no improvements and/or big changes compared to the pre-expansion game. One big hinderance though were the loading times fort the scenes. I don't mind LOP hosting the files on their server-side for DRM however I was often finding myself waiting an entire minute for a scene to load and more often than not it would just completely crash and I'd have to reload the page.
To sum it up the expansion itself did not feel like there was a large improvement on the current game. The core gameplay and events remained the same. There were only a small handful of scenes with the sister but they did add some new scenes with Serena and improved the story which was a nice touch.
The game was fun to play if you enjoy their style of games however I wouldn't consider it to be a must-play.