When I was in college the quote below was a popular one that we batted around often (I heard a variation of it @ CPC 2012):
What you call people with is what you call people to. What you call people to that you must sustain.
If you do ministry with hype and prize giveaways, then that us what your calling people “to” and you have to sustain that pace. I think you can have fun, but that should be secondary to sharing the life of the Gospel.
Having fun and doing goofy things should be a part of ministry because it’s part of being human.