There are a number of fundamental features you can interact with in the Nekopara series.
The option to set the chest bounciness determines how sensitive a bust will move with the physics while their sprites are in motion. It can be set to zero to disable bust motion. Note that this graphic option only applies to female characters with sufficient bust sizes.
This feature is only available in the uncensored versions. The option will allow animation in H-scenes. When you access the Extra menu and view the H-movies, the animation, voice and sounds are present even if this option is off, and volumes turned down.
WARNING: The animations are in GIF format, so it might lag on some computers with it on.
The P-key is a famous feature and easter egg in the series. Pressing "P" on the keyboard makes the characters on screen bounce.
There is a similar feature to the P-key that only works when you play the game in windowed mode. Dragging the window will make the characters bounce in different directions.
Microphone and BacklogEdit
Clicking on the microphone beside the name of the voiced characters repeat their lines. The backlog can be accessed by scrolling up with the mouse.
Petting is a feature that was first introduced in Nekopara Vol. 0 which allows the player to "pet" one of the Catgirls or Shigure on screen. Located on the upper right of the game client is the "Pet mode", to which is turned on and off by clicking the button once to turn on then once again to turn off. Using your cursor, the player can now pet to your hearts content! This enables you to achieve the petting achievements on steam. The sounds were changed in Vol. 2 and the characters have different reactions copied from other characters.