| easy | medium | hard | |
|---|---|---|---|
| Beginner #1
| [1] | ||
| Beginner #2 ("concentric 'C's")
| [1] [2] | ||
| Intermediate #1 ("crop circles")
| [1] [2] [3] | ||
| Intermediate #2 ("archipelago")
| [1] [2] [3] [4] | ||
| Advanced #1 ("volcano")
| [1] [2] [3] [4] | ||
| Advanced #2 ("pipes")
| [1] [2] [3] | ||
| Expert #1 ("clock")
| [1] [2] [3] | ||
| Expert #2 ("castle walls")
| [1] [2] |