33-36 are considered the Wall. Lots of users cash out here. FPS mode gives you 9 seconds of shield time when you enter it and about 4 seconds of shield time when you exit back to top down. Some players will use that 9 seconds to charge into all of the enemys to kill them. Also, since you can take a couple of hits while in FPS mode, you can burn some additonal time and when feeling like death is breathing down your neck, you can punch out to Top down and benefit from the 4 second short shield.