Unperishably Thumbnail of a Unperishably puzzle.

Size:
12x12.
Elements:
U, N, P, E, R, I, S, H, A, B, L, and Y.
Groups: Thirty-nine total.
The 12 rows.
The 12 columns.
The 12 4x3 rectangles.
The 2 eyes.
The elements that make up the smile.
Instructions:
Precise details on group numbering.
Answer grids:

Puzzle Difficulty levels and Examples

Difficulty LevelLowHighExample
Easiest 2 2 Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Easy 3 4 Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Medium 5 8 Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Difficult 9 14 Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Challenging 15 20
Tournament 21 29
TournamentPlus 30 45
Perplexing 46 60