The phrase "to solve the riddle" means to find the answer or solution to a tricky or puzzling question or problem that requires thinking and cleverness. Full definition
I liked the abstractions better, but either way, I had to forget the pretense of solving the riddles of art and nature. (haberarts.com)
Scrap from an old particle accelerator helps solve riddle of how chemical elements are created in supernovae (newscientist.com)
With the introspective look at the development of the character over the course of the game, the puzzles will no doubt offer some non-traditional experiences, possibly providing the player with a deeper meaning rather than just solving the riddle at hand. (playstationenthusiast.com)