Can multiple games be started at the same time?

Yes, as of software version 2.20 this is possible for group games. For individual games, this was possible before. It works like this:

1. Scan the starting ticket of the game you want to play.
2. Keep the Picoo controller(s) of the players who want to play the same game near the playmaker. 
   1. Keep the controllers of the players who do not want to participate away from the group.
3. Wait until all controllers of players who want to join are white 
   1. The controllers of the players who do not want to participate should still flash blue slowly. 
4. Press the playmaker button to start the game.