If you haven't patched the game yet you should.
You just need to type "r18" in the main menu and the patch should be applied

There are 15 levels in this game: 12 that can be viewed in the CG section of the menu and 3 that is exclusive to the "Play" section.
I'll show some pictures here but I won't show some because I think that they are too "intense" for Steam. I'll instead put a link to the corresponding picture.

Gameplay

Each level has a different number of pieces. You can place the pieces anywhere but to finish the level you must connect the right pieces together.



The top left picture and the lower right picture shows two different correctly combined pictures and the lower right picture shows two wrongly combined photos.

Level 1

This level has 15 pieces.

Level 2

This level has 12 pieces.

Level 3

This level has 15 pieces.

Level 4

This level has 15 pieces.

Level 5

This level has 15 pieces.

Level 6

This level has 12 pieces.

Level 7

This level has 12 pieces.

Level 8

https://drive.google.com/open?id=1UEuqaw4mUac0JpXrZ6LYQvoUcRX8tmBe


This level has 15 pieces.

Level 9

This level has 16 pieces.

Level 10

This level has 16 pieces.

Level 11

This level has 6 pieces.

Level 12

This level has 6 pieces.

Level 13

This level has 16 pieces.

Level 14

This level has 16 pieces.

Level 15

This level has 15 pieces.

Okay so this game has over 1500+ achievements and I won't list how to get each one as obtaining all of them uses the same steps. You would get around 1000+ achievements by finishing the CG's but you won't obtain all of them so I'll give you the steps in case you don't have them all.

Steps on obtaining them

1). Start the game.
2). Select Play on the first menu.
3). Play any of the levels.
4). If you get a bombardment of achievements then you did it right.
5). In case you didn't get any achievements, try loading a different level.