This was before you'd actually met though? In that case it's not ghosting - that only refers to actually having a relationship with someone, and them disappearing.
It's easy to overinvest with someone you're talking to a lot, but until you've actually met them, you're just having a relationship with a fictional character, invented by your own imagination, based upon photos and words on a screen. That isn't the real person, it may be a very close approximation but it could also be radically different.
You've met the man once. He's been possibly a bit flaky (5 days without messaging would imply he's not that into you, he was meeting someone else, possibly)
But that's dating..
You've only met him once. Put the phone down for twelve hours or so, wait till you feel breezy and chatty, then message him. This isn't about playing a game and making him wait, it's about taking control of your own actions, which will both make you feel better and also make you more attractive, and less needy, to him.