Bottles can be thrown to distract enemies from their patrol routes, but this clip shows that all player actions can be reversed at will. Just by pressing a button, time can be made to flow backwards so that broken bottles can be unshattered and set down again, intact.
Implementing the time reversal mechanic was a very in-depth process that involved writing code to capture and store world-states, including all states of all components, whether they were written by me or native to Unity. World-states are captured and recorded several times per second, and they are restored as the player reverses time. Interpolation between these previously recorded states is done so that the time reversal effect appears smooth.
This breaching scenario showcases the player's ability to slow time, shatter doors, use flash bombs, throw knives, fire upon enemies, and reverse time in order to achieve a better outcome. Guards draw weapons to attack hostages and the player, but can be stunned or killed by player attacks, depending on where on their hitboxes they are struck.
This clip also features an early revolver-style wand, which shows clearly how many shots the player has remaining. Early feedback suggested that this weapon seemed incongruous with the fantasy setting, however, so it was replaced with the reverse-draw crossbow shown below.
This reverse-draw repeating crossbow was modelled and animated in Blender using a combination of bone deformations and blend shapes to make it fire and cycle through the bolt chambers realistically.
Since the fact that the bolt has to strike where the camera is pointing is at odds with the fact that the crossbow is held low and off-center, a special technique is used to reconcile them. Each time the crossbow is fired, a raycast is first projected forward from the camera into the scene to determine where the bolt strikes. The bolt's trajectory from the tip of the crossbow to the point of impact is then computed so that the bolt's trail and rotation appear physically accurate. Since the crossbow is always pointing toward the center of the screen, the crossbow and bolt trail always appear to be aligned from the player's perspective.