Cascade: One of the best Sudokus I've featured

Today's Video:

Another debut with flipout today. I don't think I am exaggerating in saying this amongst the most enjoyable puzzles I've played period.

You can rest assured I will be checking flipout's back catalogue promptly!

Link to Play:

Cascade by flipout https://tinyurl.com/SudokuSleuthCascades

Rules:

Normal sudoku rules apply.

Killer: digits in a cage must sum to the total in the cage's top left corner. Digits may not repeat in a cage.

Global entropy: each 2x2 set of cells in the grid must contain at least one digit from the low (1,2,3), medium (4,5,6), and high (7,8,9) entropy sets.

German whispers: adjacent digits along a green line must differ by at least 5.