Atrox footprint
If you kill someone or step in oil or mud, walk on cement or somewhere clean and look at your footprint. It will be in great detail and read "Atrox" at the top/middle of your shoe print. "Atrox" could be a reference to a type of snake, a band, and a television show or movie.
Beat final Boss
In the fight with Dr. Krone's gigantic Sentinel, when you destroy one of his guns with the Pulse Gun, Krone will send artillery raining on your roof. In order to escape this barrage, slow time and go into the far right corner. Face the wall and up at Krone's Sentinel. Jump up on the platform. Keep running to the right into the corner. You will take no damage while in that corner. This works for all three barrages.
Blocking the wind fans
When you face the first wind fan after coming from the tunnel, there are four platforms around the fans. On any platform facing towards the wall, reverse time. Do not let your time energy disappear completely. Before the time energy is completely gone, stop time and go over to the platform.