Sadly, the return key can't be discussed by the key-pressed block! It doesn't show up in the menu, but by using the "join" block (or a variable reporter), we can insert that name into the input and it should work! No /guarantees/ this is added since it's coming in a future update and the ST may find that it's not quite ready to be released after they do testing, buuut... if it gets released, you can find out with this project! :) Only enter, sadly still no support for shift, control, etc. Those are special accessibility-related keys, so it's not very likely that Scratch will ever see them added, but who knows. :P