Debug mode is activated with "ip_debug 1" in the console, which is opened with ~.

Keys

• F: Go to the next respawn point, press again to cycle between them
• H: Return to 47's POV if you are in the POV of an NPC
• I: Go to the next cutscene
• J: Jump. This is presumably a partially implemented mechanic
• K: Toggle free camera mode. The camera is controlled with the arrow keys. AVOID RUNNING while in freecam mode, it will increase the camera speed to crazy-fast speeds
• O: Toggle top-down view. 47 can be controlled in this view
• T: Toggle wireframe mode
• Y: Toggle drawing through walls
• 0: Cycle lighting mode between full, flat-shaded, and static shadows only
• F11: Draw NPC pathfinding nodes
• F12: Kill NPCs at the crosshair location and toss them in the air
• Tab: Go to the POV of the next NPC
• Shift+Tab: Go to the POV of the previous NPC
• Shift+F3: Show the audible range of sounds
• Shift+F5: Show door visibility portals
• Shift+F6: Show light information
• Shift+F7: Show camera positions and directions
• Shift+F8: Draw an x/z coordinate grid at the origin (x=0, y=0, z=0)
• Shift+F9: Show collision volume of 47 and model attachment points. Press it again to move normally
• Ctrl+F9: Teleport to the crosshair location. Also works in free camera mode. It has to be a flat surface.

This video guide (in Russian) has a demonstration of how to use debug mode beginning at 2:09