A little more than halfway through, the level diverges into two main paths.
The first is an underground path:
The other is suspended on brick platforms:
No path is really better than the other. The underground path is a shortcut, but the other path provides the oppertunity for two extra lives.
Level 1 is very near to completion. To be honest, I don't think I'll add the boss right now. I'm actually debating whether this game will have bosses.
I remember SMB3, which I base this game off of partially, which had boss battles. I found those boss battles rather boring, and to be honest, I don't know how to make exciting boss battles in this game. But, I'll see what I can do.