Whenever I make starting levels or intro levels, movies, etc., I always make about 7-10 levels with the exact same thing only with different names. Then I have something like this...
NPC Code:
if (playerenters)
{
if (isleader)
{
movie code, or whatever else;
}
else
{
setlevel2 nextlevel,playerx,playery;
}
}
Then the level won't reset when someone enters unless they are the leader, and you will get warped to another room if you are not the first person. When you get to the last room and it is still occupied, set the warp to the entrance.