It's too complicated to explain here, but the following URL will help:
http://www.YouTube.com/watch?v=Iu9zPfuNnfo
it is not stars it is a world
Collect 120 stars
When Mario repairs the castle with the star that bowser gave him peach comes. she says "Mario! the power of the stars has repaired to the castle. And it's all thanks to you. thankyou Mario." then peach kisses Mario and bakes him a cake like she promised. and when you get 120 stars go ontop of the castle, talk to Yoshi and he gives you 100 lives.
Waluigi isn't in that game. The cannon in the castle grounds is unlocked with 150 stars.
To get to the top of the castle on Super Mario 64, there are two ways. The first is to get a running start (running towards the right side corner of the castle), jump on the castle wall, then on the grass, then back on to nearly grab onto the edge, and get on top of the castle. The second way is to get all of the stars, then a cannon will be accessible out on the front part of the castle. Then, climb into the cannon and shoot yourself on top of the castle.
There are 35.(+the 100 coins in each 15 stages)
If you are talking about the original 64 game, there are only 120 stars. If you are talking about the DS version, you are probably missing the secret stars you get when you collect 100 coins in a level, and some of the castle secret stars.
it is not stars it is a world
You beat the game
To get on the castle roof of the castle
In all the levels, and in the castle hidden.
You can't.
Get all 150 stars.
Collect 120 stars
When Mario repairs the castle with the star that bowser gave him peach comes. she says "Mario! the power of the stars has repaired to the castle. And it's all thanks to you. thankyou Mario." then peach kisses Mario and bakes him a cake like she promised. and when you get 120 stars go ontop of the castle, talk to Yoshi and he gives you 100 lives.
Go to youtube and see how to pass the stars, ok
It's too complicated to explain here, but use the following URL to help: http://www.youtube.com/watch?v=Iu9zPfuNnfo