Possibly a way to type in a command like /spleef join or right click a sign and when there is so many players for the requirement it would run spleef for for about 20 min then go to waiting mode for enough players to join again.
This will probly get denied however thought it would be a good idea to get out there that way players dont rely on staff members to run minigames for them making more automated games whenever players want to play them