You have a choice of 9 daily Hakyuu puzzles from easy to very hard:

Level 0 "easy" puzzle
Level 1 "medium" puzzle

Level 2 "a little bit hard" puzzle
Level 3 "a little bit harder" puzzle

Level 4 "crunchy hard" puzzle
Level 5 "no walk in the park" puzzle

Level 6 "mind boggling" puzzle
Level 7 "gut wrenching" puzzle

Level 8 "El Capitan in 3 hours" puzzle