"Cheat" Functions

Some things will only work if you turn on "cheats" by running Vars.Game.cheatsEnabled(true) . It seems this must specifically be done through Lua, and not just editing the Vars table defined in plain text in Journey.exe : that table already has "cheatsEnabled = true" by default, but something changes the value to "false" right after the game starts.
"Cheats" known so far:

game:netGui():ToggleEnabled()

Toggles on/off the NetGui HUD, which lets you manually connect to some other players' hosted games in the same level lobby or disconnect from your companion, and shows their profile names.
Turning cheats off will automatically turn off the HUD.

game:pauseSystem():DebugPrevKeyFrame(game:cameraSystem())

game:pauseSystem():DebugNextKeyFrame(game:cameraSystem())

While in pause mode/screensaver, instantly goes to the previous or next keyframe (camera position/angle/etc).
There are functions already defined in DebugKeys.lua that do these when you press the keys bound to moving left/right.