First Person Mode?

Press V or C, not sure what is it in default settings.

You must have some mobile unit selected to use this.

Its not actually useful for anything, but its awesomely fun and silly.

This is useful in trolling other players =]

It's pretty deprecated. If someone wants to make a game that uses it (maybe something that plays like Sacrifice), they would need to do some engine modification to make sure it is up to snuff first.

I'm not even sure why it isn't totally disabled in ZK, but the aiming is limited to what the unit would do without direct control.

quote: It can be useful for a replay/spectator mode, one chooses a units and follows it through the game.

This is available now. Under Camera Settings, enable COFC, then go to Camera Following. Use the "Enter 3rd Person Trackmode" button after selecting a unit. Best to bind it to a hotkey.

Once following you can even use the arrow keys to switch to nearby units.

There actually is slight utility. The game tries hard to disallow overshooting (you can't aim at the sky, only at ground/enemies), but for some weapons that's still enough.

For example, some dguns bounce off water, and gauss shots bounce off the ground.