We think for younger children (4-7) play should continue until everybody reaches home but for older children it could just be until the first person gets home (unless they want to find out who came second, etc). Bearing in mind that even if a player reaches Ram they can still be sent back to the starting position if another player reveals the CPU card.
We also think players should help other players whenever possible – collaboration is great and we have designed the game so it isn’t a competition against other players but for all players to get back to Ram without being caught by CPU (but we completely understand children want to be competitive too).
Which way the players play is totally up to them – just agree the rules before you start playing.
