I think I would put all of the rest of your game script inside a group.
Code:
#ActivePass on
Your game script
#ActivePass end

#ActivePass off
Your password script
#ActivePass end


Then, have a timer that will /disable the ActivePass group after the time limit and send the message about the password. You'll also need it to start another timer to track the time it takes to type the correct password. When the correct password is done, /enable ActivePass to let the game continue.

Alternately, you can just set a variable and check that variable everywhere in your game script that has input from the user. If the variable is set, then the input is accepted, if it's unset, then the password is asked.

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