Veins finished all the Sprite scenes for the game. All 9 hostages can be discovered and collected by Voms in all the different areas of the game (Docks, Forest A, B, C, D, Farms, City, New Labs, Tunnels) except for the Old Labs, where he won't have access.
Each of these areas will have several copies of each Sprite Scene, and the players will have to find them all to unlock the animation for the gallery. Hopefully, this mechanic will expand the exploration and add more replayability to the game.
For as long as you play with the SFW option switched on, all Sprite Scenes will be replaced by the Orange Slime. Sneakingly though, you will be unlocking the actual Scenes!