One idea for creating fun in a Project is to let the Project team make a fun or cool name.
Think if the project’s name was, “The Top Secret Project” or “The WOW Project” or “The most important Project” or “The Great Project”.
Everyone in the organisation would know about it, everyone would at some point talk about it, and the team members would show a bit of smirk every time they say the Projects name.
By the way, this is the definition for Smirk:
“a smile that expresses satisfaction or pleasure about having done something or knowing something that is not known by someone else.”
A very detailed post about how to choice great Project Name can be found over at Articulate.