While playing the game you should press on the F3 key to bring up the Command Console. After that you can lookup below what cheats there are and what their codes to enter are. To list all the COMMANDs you can use, open the console in-game and type in help.

Effect	Code
Abandons submarine editor. You may need to use command control (character) to restore control over yourself and command lockcamera (character) to remove freecam command's side effect.	gamescreen
Above thing, but on specified player. I'm not sure if this command is real.	heal (player name)
All hulls in a submarine have set oxygen quality to 100%, also works on other presented submarines.	oxygen
All items and broken interactable parts of the submarine (except of walls) fully reduce their condition.	fixitems
All monsters near your submarine are killed if players don't control them.	killmonsters
All walls are fully repaired.	fixwalls
Causes you to enter submarine editor in the middle of the game. You can see waypoints of autopilot being there and edit them as well as alien ruins stuff. You can also remove gaps in the broken walls of submarine borderlining with exterior area to make submarine not take flood by them.	editsub
Instantly kills all creatures in the map.	killcreatures
Makes the submarine invulnerable.	godmode
Removes bleeding, oxygen deprivation and lost HP from yourself, but not the others.	heal
Spawns husk outside of submarine at the start of the level, but I don't know how exactly this works.	spawn husk
This spawn welding tool at cargo spawnpoints of submarine. If you submarine has more, than one you can do below command.	spawnitem welding tool
This spawns a welding tool at the second cargo spawnpoint of you submarine.	spawnitem welding tool 2
This will cause player to be spawned, but it's buggy. You may need to use heal (player) to fix this.	spawn (player)
This will make you increase water level in hulls, where you hold left mouse button and drop it when holding right mouse button. To disable it type command for second time (you should receive message: WATER EDITING OFF.	editwater
Will spawn husk inside your submarine, where player spawns. If you insert monster spawnpoint somewhere husk will spawn at that specific point.	spawn husk inside