Dropping the metal box from the ledge in the Sewers
In the sewers, there is a ledge where Claire can boost Moira up to reach, there is a small metal box Moira can pick up to drop down to allow Claire to go up as well. If the box was dropped, it will appear in Barry's scenario as well, and this allows Barry / Natalia to reach the Firing Rate Lv. 3 custom part. Doing this will earn the A Ripple in Time award and its in-game record.
Depending on which character (Claire or Moira) defeats Neil, the main ending of the game will change in Episode 4. Claire killing Neil will trigger the Bad Ending, and Moira killing Neil will trigger the Good Ending.
Interacting with the switch in the first room visited
The switch changes the sluice gates seen at the start of Barry's scenario, and this will dictate which side Barry and Natalia can access. Once this episode is replayed and both routes were accessed by the player, they will earn the Routes of Future Past award and in-game record.