Open the link earlyOpen the game link on the device before the guests arrive. The first load needs a moment.
Go full screenUse the full screen button, or press F11 on a laptop, so there are no bars on the big screen.
Sound through the TVTurn the TV volume up and check the device volume too. Play a few seconds to test.
Keep the phone chargingCasting drains the battery fast. Plug the phone in the whole time.
A second phone for grandmaSend grandma or grandpa the co-op link and let them join from their own phone during the party.
Do a 2-minute run-throughThe day before, run the whole setup once with the kid. Casting, sound and the first level.
Wi-Fi at the venueAsk for the Wi-Fi password in advance. Keep a phone hotspot as a backup, and test the game on it once.
Do Not DisturbTurn on Do Not Disturb so no notification pops up on the big screen.