Good description, but the puzzles are not complex.
Run a roulette with billions of numbers. If the result is 0 you won, otherwise, try again, and again and again.
nothing complex
Discussion
Yea trying to simplyfy as much as I can.
Correct me if I am wrong buy as far as I know it is not 0 the result that determines the winner.
Each block has a target and the goal is to find a solution by hashing the whole block data to find a solution between zero and the target. As difficulty increases, the target is set lower and therefore it becomes harder to find a solution for the block.
yes, you are right, the difficulty changes over time
In my example, that would mean the roulette changing the number of possible outcomes/numbers.