Fundamentally, Hangman is a game of lists. You have the alphabet, the list of letters that make up a secret word and a list of letters that have been guessed.
This is why it was chosen as the project for the list unit in our curriculum. Snap has a lot of blocks to deal with lists but if you use the import Tools, you get access to even more. My favorites are 
and
The first one turns a word into a list and the second one turns a list into a sentence. Both are useful for Hangman.