I was going to play the new minigame by SethBling & Cubehamster called Missile Wars (all minigames is affected by this bug though).
When you are hosting the minigame on a normal server, as admin you can do /gamemode 1 and fly above spawnpoint and change settings in a little room up there, but the problem is that on Realms, all the Operators/Admins har their permissions scaled down to Default level, so the only commands the Realm owner and Realm operators can use is /help, /me, /tell and /trigger.