This article explains the new FPS mode in Knives Out (smartphone battle royale). It covers the differences from the conventional mode.
Table of Contents
What is FPS Mode?
Significant Change in Perspective
Usual TPS View (Third-Person Perspective)

FPS View (First-Person Perspective)

The perspective changes from the view where you could see your own back (third-person perspective) to a view from your own eyes (first-person perspective). It's closer to the world you normally see, making it a highly realistic mode.
Vehicle Driving Perspective Remains the Same

When driving a vehicle, the view returns to the usual TPS perspective. In FPS view, the field of vision is narrow, which can delay vehicle detection, so charging with a car might be a strong tactic.
Gameplay Style Also Changes
TPS Mode

In the usual TPS mode, you can spot enemies one-sidedly from a position where they cannot see you at all.
FPS Mode

You cannot spot enemies one-sidedly without revealing yourself, which is characteristic of TPS mode. A playstyle that involves moving proactively and pushing when necessary is more effective.
Differences from TPS Mode?
Cannot Camp Like in TPS

Since you cannot scout enemies one-sidedly from a hidden position, positioning and quick aiming are more emphasized. In this sense, skill gaps are more likely to become apparent.
Scouting Becomes More Difficult

The free-look function cannot be used, and the default field of view is also narrow, so you need to be more careful with scouting. Being spotted first puts you at a significant disadvantage, so scout and find enemies first.
How to Play FPS Mode?
Switch Button "ON" in Settings

From "Other" in Combat Settings, turn the FPS mode switch button to "ON". However, note that simply turning this "ON" will not switch to FPS mode.
Tap the Switch Button During Combat

Once the battle starts, you can easily switch between FPS mode and TPS mode by tapping the switch button displayed at the bottom left of the screen.