I have sorted each project into difficulty levels.
Here are the levels in ascending difficulty.
Beginner Lv.1
Beginner Lv.2
Beginner Lv.3
Intermediate Lv.1
Intermediate Lv.2
Intermediate Lv.3

Description continued:
Advanced Lv.1
Advanced Lv.2
Advanced Lv.3
Expert Lv.1
Expert Lv.2
Expert Lv.3