Surgery
They did surgery on an rdlevel
With the basics of the level editor, there are some hidden ways to edit a level as well. An .rdlevel file can be opened in a text editor to make changes to the level that couldn't be made otherwise currently.

Characters

One of the categories in the rdlevel file is called rows and will have a similar format to this:
You can edit the character name into any of the following characters (characters not available by default may have unfinished animations)
  • Samurai
  • Boy
  • Girl
  • Bodybuilder
  • SamuraiBoss
  • Paige
  • Politician
  • Miner
  • Farmer
  • MrStevenson
  • MrsStevenson
  • SamuraiGirl
  • SmokinBarista
  • HoodieBoy
  • Barista
  • Adog
  • MrStevendog
  • MrsStevendog
  • Purritician
  • Tentacle
  • BoyTangzhuang
  • GirlCNY
  • BoyRaya
  • HoodieBoyAlternate
  • FarmerAlternate
  • HoodieBoyBlue
  • Lucia

Settings and Mods

At the top of the rdlevel file you can add mods to your level to make it behave slightly differently.
The list of mods that can be used are:
Mod
Effect
noSmartJudgement
Changes hit timing rules - makes it so if you miss a note late enough that it's a hit for the next note, it's still a miss for the first
adaptRowsToRoomHeight
Automatically move rows closer or further apart when the room size changes
noDoublePulse
No special double/triple pulse animations
showHitStripOnlyOnActiveBeats
Hitstrip only appears in rooms where there are active beats
smoothShake
Replaces screen shakes with a smooth version
rotateShake
Replaces screen shakes with a rotation shake
wobblyLines
Oneshots turn wobbly, and wobble when hit
bombBeats
If you place a freetime that starts on a hit, it will be a bomb, and miss on hit
disableRowChangeWarningFlashes
Disables row change warning flashes when changing a row from CPU or another player
noOneshotShadows
Removes the after effect on short oneshots
Another setting changeable through surgery is firstBeatBehavior, which by default is RunNormally. You can change this to RunEventsOnPrebar to make any action events on bar 1 beat 1 happen before the level starts.