Can you guess my random number? Set the upper bound. You have 8 guesses. Your upper bound is your score (if you succeed).
The game will generate a random integer between 1 and {upper_bound}, inclusive. It will then prompt the player to enter a guess, indicating if the guess is too high or too low. If the guess is correct, the game will print a congratulatory message and compare the player's upper_bound to the current high score. If the upper_bound surpasses the high score, the game congratulates the player and update the current high score on file.
A custom variant of the number guessing game in chapter 2 of The Rust Programming Language book.