For this week's challenge, the theme is solving puzzles "two under par", meaning with two fewer moves than the level number suggests.
The 3 codes of the puzzles are: 9667-09, 4997-10, and 2344-11.
To play these puzzles, you first have to unlock level 9 in the full game by solving puzzles on levels 1 to 8. Then you start a game with NEW GAME (in the main menu) and select CODE instead of a level to enter the first code. By solving that puzzle, you unlock level 10 and can enter the second code, and so on.
For everyone, who doesn't own the full game, here is a "two under par" puzzle on level 7: 5756-07.
Going forward, I'll probably change the weekly challenges into videos showing me playing icosi-do and thinking aloud. The challenge would then be to solve the puzzles faster or in fewer moves than I did. Also, if you get stuck with a puzzle, you could look at my solution for hints. Please let me know what you think of this kind of challenge.