While in level press the [~] key to open the dev console
All Weapons/Ammo - bighugmug
God Mode - vivalahelvig
Fly Mode - heehoo
commit suicide - Kill
Change Camera - camera1, camera2, camera 3
Jump to level - levelsp [ .rfl filename]
Changes to the specified level. If run as a client while that not connected to a server, the level will be loaded in single player mode. If run as a server (or via rcon), the server will switch to the level in multiplayer mode.
dm01.rfl
dm02.rfl
dm03.rfl
dm04.rfl
dm05.rfl
dm06.rfl
dm07.rfl
dm08.rfl
dm09.rfl
dm10.rfl
dm11.rfl +
dm12.rfl
dm13.rfl
dm14.rfl
dm15.rfl
dm16.rfl
dm17.rfl
dm18.rfl +
dm19.rfl
dm20.rfl
ctf01.rfl
ctf02.rfl
ctf03.rfl
ctf04.rfl
ctf05.rfl
ctf06.rfl
ctf07.rfl

you can also type in help for a list of commands
mostly for multiplayer
got most info from https://redfactionwiki.com/wiki/Red_Faction_Console_Commands

Duplicating Remote Charges
Toss a remote charge on the ground or a wall. press the use key to pick it back up, by default this is Enter. you now have 1 more charge. the most you can hold is 21

Secret Movie
this can be found in the game files
Data-Movies-Technochunk
enjoy

Bonus Level Called Glass
this is located in the extras from the game menu
you are given infinite rocket launcher and charge ammo to shoot up a glass house

infinite fusion rocket launcher ammo
well playing multiplayer with the fusion rocket launcher use all but the last shot. kill yourself and when you come back you will have a rocket launcher with 4 ammo