Here is an interesting idea for showing your game to a “sponsor”.
Have your tutorial level then have the game “jump” to level (lets say 5, one of medium difficulty), then after that level have it “jump” again to something of a harder difficulty. Or instead of dificutly where in the game more of your “epic” stuff is opened up. This way they can get a broad view of what the game is about. Also if it is story driven you would need to put in something that say x, y and z happened in the previous level so they can understand why you are doing x thing in the current level.
For the actual released version you would have everything lined up properly without all the “jumping” around.
This is just an idea, instead of jamming all your cool stuff into 1 level.