I have been constructing Sudoku variant puzzles since Summer 2021. I regularly post my puzzles on Logic Masters Germany, which you can find and play below.
The star rating denotes the difficulty of the puzzle, whereas the percentage below it denotes how enjoyable the puzzle is based on solvers' feedback. 5/5 stars being the most difficult, and 100% being the most enjoyable puzzle. If the stars are blue or if the percentage is not present, then not enough feedback has been received to decide a rating. The blue stars are an estimate of the difficulty from the puzzle setter. If you have no experience with Sudoku or its variant puzzles, I would recommend clicking on the "Puzzle portal" menu and checking out some puzzles with 1/5 stars for difficulty, and slowly moving upwards.