Super Mario Galaxy Easter Egg - Hidden Star Bit Life-Rainbow Chamber

Go to the Terrace and go to the Honeyhive galaxy (2nd from the Observatory). Choose the 3rd world, the "Big Bad Bugaboom."
On the right-hand side of your screen, you will see a small wall between two hills. Jump over the wall into the puddle.
Continue forward, away from the puddle. On the left-hand side of your screen, you will come to a recession with a coin inside. Wall-jump to the top and exit to the right.
Towards the left-hand side of your screen, you will see an "M" in the sky. Use your blue star cursor to collect them.
Use one of them to shoot the plant growing out of the pipe (using the B button). Spin into it.
Collect your star bits, then go down the pipe.
(Note: The boulders only roll along their circular paths, "burned into" the boards.)
Use the ramps to go to the bottom floor, avoiding the boulders.
Jump into the giant coin and capture the star to become Rainbow Mario.
Now, run into the boulders for star bits. Remember that to move between the walls, you must use the ramps.
Remember to collect your star buts, then use the ramps and, avoiding any remaining boulders, go back out through the pipe.
Then, jump down the recession and go back into the puddle and over the wall.