First of all, good job devs. I can tell you have been taking feedback from the first mosaique games to heart with the making of this game. The game looks good so far and runs better than before.

Suggestions:

1. Tutorial
There aught to be a tutorial, even though the controls are so simple. Even just one screen explaining it before the first puzzle would be good. "Left click turns CCW, right click turns CW" is enough really. Then as more mechanics are added, explain the new controls. Once a mirrored puzzle is first opened, tell them the puzzle includes mirroring as well as a short explanation for the mirroring controls such as "Middle click mirrors the piece horizontally" or something along those lines. You've already done tutorials like this with the first time you open a multi-phone puzzle, it only makes sense to do it with the earlier puzzles too.
Heck, if you want to make the tutorials more interesting story-wise the character could have a boss at his IT shop who shows him the ropes. Could make for some funny dialogue too when he finds that you're only recovering lewd data of your clients. This isn't necessary though, just could make the tutorial a bit more lively. A text screen really is enough.

2. Middle click
Thanks again for implementing middle click. It's helpful but a bit wonky sometimes. Sometimes instead of mirroring it will act as a regular click for the first use, and then mirror after that. It's a bit strange to use because of this, but it still helps a bunch.

3. Mirroring Mechanic revamp
Given that middle-click is now a thing, I think it might be advantageous to change how mirroring works in puzzles. I believe that if a tutorial is implemented (see 1 above) you could change it so that pieces do not mirror using left/right click, but rather only on middle click. This would help the mirroring mechanic make more sense, as well as fix the issue of #2 above

4. Dialogue
Dialogue scenes are a nice touch, but a bit painful to navigate. Take pretty much any VN as an example and there's a lot missing here. A continue button isn't really necessary, a left click anywhere on the screen should progress text. A left click while text is still scrolling should show all the text at once instead of advancing the text.
Those are my biggest issues for the dialogue , but there is more features you could implement from other VNs such as:

• "Auto" function. Auto progresses text a short while after the whole text box has been displayed
  
• "Log" function. Press a button to bring up past few lines of text. Very useful if you accidentally skip a line
  
• Scene viewer. Part of the gallery. Allows you to re-read dialogue sessions whenever you want
  
• Dynamic CG. Changing the girl's CG as she talks helps keep it interesting, Something as simple as changing her facial expression makes it much better. Ex. Girl comes up all sad because she broke her phone. The CG has a sad face. She asks if you can fix it, you say yes, she's happy. The CG changes to a happy face. Later on, when you notice the pictures are lewd, she gets embarrased. The CG changes to a blushing face. etc etc. The way it is now works, but something like this could help up the quality of the game, if you're willing to put the effort into it.

5. UI
The menu UI is a bit confusing. In particular the "Girls" menu. The way you select puzzles is a bit strange. It's a nice fluid aesthetic, but i dont think that really helps with a progression-based puzzle game. There aught to be more organization. I think what you had in the earlier mosaique games was better, where you categorized puzzles by girl. In a similar light, I think the finished puzzles should also appear here. It's a bit tedious to have to go back through the gallery to replay them that way, and having them on the girls page would help to keep the menu structured better.
If I were to remake this girls page without sacrificing the current aesthetic, heres how I would do it: Display every available girl in the same manner they are now, with the little circles. However, these circles would be connected to the girl, not a specific puzzle. Clicking on a girl's circle would bring up her profile, as well as a list of available puzzles for that girl inside the profile. Completed and uncompleted puzzles would be visually different. Perhaps a checkmark on completed ones, or a glowing portrait around uncompleted ones. Clicking on a puzzle would bring you to the workshop for that puzzle.
If it sounds a bit confusing without being able to see it, feel free to ask for clarification and i can draw something up.

6. Reset progress button
A button to completely wipe your save, including level-ups and story progress. There was one in the first two games, but I cant seem to find one in this game. Very important feature for a primarily puzzle-based game.



Suggestions that are more my opinion than anything (take with a grain of salt):

1. "Click to fix the phone".
Is this really necessary? It doesnt really fit in with the rest of the game, I find it just sorta disrupts the flow a bit. Just my opinion though.

2. Forced dialogue
Some of the dialogue is a bit forced, in my opinion. I understand it's harder than it looks to write dialogue but theres a few words you could omit or add in to make it feel a little more realistic. For example, the dialogue when you unlock the second girl.
The first girl says something along the lines "I have a female friend who could use your help, I've told her to come to you"
The female here really isnt needed and it just feels like its trying to force the whole lewd aspect instead of making the dialogue sound realistic. A normal person would just say "I have a friend who could use your help, I've told her to come to you." This sounds much more natural, and still shows that her friend is female through the word "her".
Its not that the dialogue is bad, it just feels a little unnatural. I completely understand having issue with it though, dialogue is hard.

3. Pseudo-Censoring
In the original games when you got to a puzzle with nudity in it there would be stars/beams of light over the nudity at first. Only once the puzzle was complete would the stars/light go away showing the goodness below them. I liked this touch in the old games. Keeping the good stuff out of sight until the puzzle is finished gives a bigger reason to get to the goal in the first place. Opening the puzzles in this game and immediately being able to see the nudity before even starting makes the final reveal a lot less satisfying.

Bugs:
Achievements are not unlocking.
Sometimes you are unable to rotate pieces in any puzzle. The only fix is closing and reopening the game.
Dialogue text scrolling sound sometimes keeps playing after dialogue is finished
Not sure if it's a bug, but some small pieces just show up as boxes with x's inside of them. I'll get a screenshot later.


All in all the game is looking to be an improvement on the past games in the series. Good job, dev.
If I find anything else to look at as i play more, I'll add comments here.