Well, are you wanting to have a loading time (perhaps small) in between each level? Or are you anting on the fly?
Well, when you rwach the middle of the tunnel, you would free all the entities (using FreeEntity) then use load entity to load in the new level. Then position the world back to 0,0,0 and position your character to where he should be for the beginning of the next level.
Well, when you rwach the middle of the tunnel, you would free all the entities (using FreeEntity) then use load entity to load in the new level. Then position the world back to 0,0,0 and position your character to where he should be for the beginning of the next level.