Ideas for a simple gender reveal party

We find out gender in about 3 weeks and plan to do a small reveal party with powder cannon roulette (5 white cannons and 1 cannon of the right color). We are planning to just invite 4 of our best friends, siblings, and parents to our house. Not sure how to lay out the party as we don’t want anything too big. Do we play any games? Do we just take guesses and have food and drinks and then shoot off the cannons? We will have some family driving almost 3 hours to come so we don’t know how ‘big’ to make it without going over the top. And help or advice would be great!