The best replacement for puzzle is mystery.

The best alternatives to puzzle are rated as following:
★★★★★  mystery
★★  riddle
★★  word search
★  trivia
★  maze
★  crossword
★  puzzle
★  jigsaw puzzle

Your alternative for puzzle is not listed? Suggest!
Speaking about puzzle, one probably shouldn't forget about lifting pencil.

Other search terms related to puzzle and their ratings are:
★★★★★ lifting pencil
★★★★ most pieces
★★ extra pieces
You have in mind a companion for puzzle and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of puzzle in all years. Click on graph for more.
puzzle
mystery
riddle