These rooms are perfect to bring large groups together at once. They're also a popular team building event for groups looking to play whilst working from home.
I recommend you buy enough for one room pass per player/device which gives each person full access to the room and allows everyone to interact with the clues on their own device.
It is also possible to play with one pass per team and have a team captain share their screen which works fine but does leave one player per team doing all the heavy lifting!
The more passes you buy, the cheaper it get per head! Just choose which room you fancy doing then select the price range based on your number of players on different devices, input the number of players you've got and hit buy! You'll then be able to allocate to each player in their group using their email address, directly from your account!