Super Mario 64 is a great game to play. But did you know there is a game spoiler that allow you to complete the game with hardly doing anything?
First of all, before we start, let's learn Backwards Long Jump, It occers when you do a long jump, then, face the analog stick in the other way, we'll jump back to that later. (Get it? Jump? Yes? No?) Second of all, you just need 15 stars, and later in the tutorial, you should gather 16 stars altogether.
Go into the basement and find Mips the Rabbit. Mips will help you glitch through the 30 star door. Catch him, and you should get a star, Do not get it, otherwise Mips will run away. Now, take him to the door leading to the 30 star door, go to the corner of it and turn a bit to the right. Let him go and you should glitch though. It might take some trys, but when you do, press Z to crouch, then crawl and face Mips. Take him to the other side and he should get through. When you do, Mario should automaticly open the door for no reason and he should be there. Take him to the 30 star door, and walk to the wall next to it, when you get to about the corner press Z to crouch and you should glitch though. You have successfully bypassed the 30 star door. Then go into Dire, Dire Dox and get a star, taking your number of stars to 16. Now you can battle Bowser in the Fire Sea. When you return from victory, re-enter Bowser in the Fire Sea and press "Exit Course" in the menu. Now you should return to the castle. Go to the door upstears and you should be able to open it with the key you got from battling Bowser. Now, remember the Backwards Long Jump I mensioned earlier? Do that on the stairs in the key door. When you land, keep pressing A as fast as you can, and Mario should go "Y-Y-Y-Y-Y-Y-Y-YAHOO!" whilst sliding on his bum. You should glitch through the door. Then go upstairs leading to the 70 star door with the endless stairs. "You will need 70 stars to pass The Endless Stairs! Bwa ha ha!" -Bowser. Well, Bowser, I can tell you that's a load of old garbage. Do the backward long jump on the stairs and like Mario did earlier, he should go "Y-Y-Y-Y-Y-Y-YAHOO!" and slide through his bum. You should do it enough to pass the endless stairs without 70 stars. Go into the hole and battle Bowser. And there you have it, you just passed Super Mario 64 with 16 stars only! Have fun!