Any ideas for my ROBLOX Mario based game?

I have the first level ready:

Level Overview

Dodging the boulders coming down the hill

Bouncing mushrooms

Moving platform

Dodging multiple boulders coming down the hill

The end of the level

And the second level is almost done:

Start of the level

BULLET BILL!

Mushrooms that tip on both sides

Jumping over snowballs

Any ideas?