Press the back quote/tilde (` / ~) key to open the console, default commands are shown by executing 'help'

After the console is open you can press tab to enter lua mode, note the commands on this list WILL NOT WORK in lua mode.

• kill | kill all enemies in the city
  
• rich | gives you 1000 rep and 30 power cores. Rep disappears after completing an island.
  
• event <name> | add event
  
• incident <name> | add incident
  
• invasion | add invasion event
  
• anim <name> | test animation
  
• sanim <name> | test animation (on board square)
  
• reload | refresh lua scripts
  
• day <number> | set the current turn. Day 0 is the first turn, day 1 is the next turn. You can input negative numbers.

• unlock all
  
  • Gives message on execution "Sorry, this command no longer works in the release version".
    
  • It is unknown what the original purpose of this command was.
• resolution <width> <height>
  
  • Changes resolution of the game window.
    
  • Specify resolution in pixels.
    
  • Minimum resolution 800*600.
    
  • Can have odd resolutions e.g. 2560x600.
    
  • Crashes the game if arguments are not passed properly.
• makeitso
  
  • Gives player all pilots.
    
  • Does not give the player secret/special pilots
• unlock ach
  
  • Gives player all achievements.
    
  • Achievements are given on steam.
• ach <achievement_id>
  
  • Gives the player the specified achievement.
    
  • e.g. "Global_Victory_Any".
• debug
  
  • Toggles debug mode.
    
  • Enables the use of more commands.
• popups
  
  • Unknown effect.
• music_version
  
  • Toggles between "music version 1" and "music version 2".
    
  • Unknown effect.
• gog_clear
  
  • Clears all achievements in the gog version of the game.
    
  • May only work once.
    
  • Unsure if this has any effect outside of the game.
• steam_clear
  
  • Clears all achievements in the steam version of the game.
    
  • May only work once.
    
  • Unsure if this has any effect outside of the game.
• human <pilot_id>
  
  • Unlocks specified pilot for player.
    
  • creates "Pilot Found" popup.
    
  • Popup displays incorrectly if no argument specified.
• populated
  
  • Unknown effect.
• pod
  
  • Spawns a timepod.
    
  • Multiple timepods can exist.
    
  • Can only collect rewards from one pod per mission.
    
  • Spawns special ftl pods if the secret command is used prior.
• rain <value>
  
  • 0 = off, 3 = default rain, 6 = heaviest rain.
    
  • Outputs "set rain to <value>" in console.
• rain_type
  
  • Disables rain during a mission.
    
  • Outputs "set rain to 0" in console.
• pawn <pawn_id>
  
  • Spawns a unit with the given pawn name.
    
  • e.g. "PunchMech".
    
  • Can have many units of the same faction e.g. player faction
• win
  
  • The player instantly wins the given mission.
    
  • Using this on the final island first stage will send you to the next stage instantly.
    
  • Using this immediately after beginning the final island second stage results in Bad Things. The screen will show the second stage cutscene while the voices scroll through what everyone normally says, but the reinfield bomb does not prime. To fix this go to main menu then re-enter the game.
• power <value>
  
  • Adds/subtracts grid power and defense. Note that grid defense from bonus power after the bar is full cannot be subtracted.
• secret
  
  • Damages an Icesheet / Mountain and gives it the secret ftl distress signal. There must be a Icesheet / Mountain in order for this to work.
    
  • The event continues as normal to get the ftl pod
    
  • Using this command makes all future pods special ftl pods
• morale <value>
  
  • Adds/subtracts the specified grid power. Excess power increases grid defence.

pressing tab whilst in the console will enter lua mode
money <value> | Gives/subtracts the number of reputation specified.
people <value> | Gives/subtracts the number of civilians-saved specified.
cores <value> | Gives/subtracts the number of power-cores specified.
weapon <weapon_name> | Gives the weapons specified, if no weapon is specified a random weapon is given.
pilot <pilot_id> | Gives the pilot specified, if no pilot is specified a random pilot is given.
xp <value> | Gives/subtracts the number of xp specified to all pilots, can level up, cannot by de-leveled.
repair <value> | Gives/subtracts the number of repair kits specified. Unknown effect.
text <event_name> | A pilot will say their line for the event specified, if no event is specified a random line is given instead.
turn <turn_number> | Changes the turn number, meaning the victory in 'x' turns also changes.
reward | brings up the perfect island rewards.
instantwin | Instantly wins the round.
end | Instantly wins the round.
victory | Causes you to win the game.
snow <value> | Enables snow. Unknown effect of value.
resist | Executes resist special effects.
final | Causes final island to appear instantly.
upgrade | Unknown effect.
corp <corporation_name> | Unknown effect. Prints "That corpotation does not exist" if value incorrect.
mission <incident_name> | Unkown effect. Crashes game without argument. Presume it provides mission rewards.
store | Brings up the store to acquire and sell goods.
mapedit | allows you to create your own maps, requires debug mode enabled
map | Unknown effect. Prints random (map?) names.
save | oh and the save commands saves a preset for the "undoturn" command, or just general turn resets (it only seems to save enemies though). (Thanks to @køt for the information)
undoturn | Loads the last undo save.
history | Outputs history of moves and attacks. (Thanks to @krzysiu for the information)
hide | Hides ui elements.
loadfonts | Reloads fonts.
test | Unknown effect.
unlock ach | unlocks all achievements, Including Steam achievements.
explore | reveals island missions.
final | allows you to access the final mission.
secure | Secures one island at a time, going left to right. Functions on the screen that shows all the islands.
zoom <value> | changes the zoom level of the mission view.
timeline | unknown.
boss | It will trigger the spawn of the Vek Leader mission for an island. (Thanks to @Xenesis for the information)

[add mutate | Sequentially adds mutations to all enemies. Final message is "Added mutation: LEADER_BOOSTED.
Current mutations: LEADER_FIRE, LEADER_TENTACLE, LEADER_REGEN, LEADER_HEALTH, LEADER_EXPLODE, LEADER_ARMOR, LEADER_SPIDER, LEADER_BOOSTED".
"boosted_psion" has no text associated with it if you view an enemy's conditions
clear mutate | Resets mutations "Mutations cleared!"
print mutate | Lists enemy mutations
backups | Toggles backups. "Save Backups Disabled" "Save Backups Enabled"
export_steam_achievements | Unknown effect. No message.
export_stadia_achievements | Unknown effect. No message.
hidebarks | Toggles barks. "Barks enabled!" "Barks hidden!" Something to do with Pilot Barks?
human | Unknown effect. No message.
joystick | Toggles L-stick coordinates in console.
set language <name> | Sets the UI language. English english schinese french german italian polish brazilian russian spanish japanese korean tchinese Chinese_Traditional latam Spanish_LatAm swedish Swedish thai Thai turkish Turkish arabic Arabic chinese_simplified portuguese_brazil chinese_traditional spanish_latam
setting <name> <value> | Effects unknown, message is "Setting <name> set to <value>"
sounds | lists some sounds
tut_reset | resets tutorials
alert <message> | Displays a message with a callout line.
clearbusy | Unknown effect. No message.
crack | Unknown effect. No message.
display | Synonym for hide
dropin | Mechs drop into level, then seems to run the pop command.
mapinfo | Displays "Map name = <map name>"
ping | Highlights square (3,3) relative to bottom right corner.
pop | Plays start-of-level messages, lists messages played.
scale <number> | Rescales the UI. Accepts fractions. "scale 0.1" is amusing. Negatives seem to be treated as "2".
tileset <name> | Loads a tileset: snow, grass, volcano, others? Invalid values results in some visual artefacts until a valid tileset is loaded.
time_travel | Runs the end-of-game teleport sequence. Leaves empty/dead mechs on a normal map without ending the game.
state | Displays start-of-turn banner similar to "Player turn <br> 4 turns remaining"
undolast | Looks like undosave TBC

I would appreciate comments that help with the following:

• Descriptions of untested commands.
  
• Better/Accurate descriptions of commands.
  
• Any commands that I have missed.