Here is a glitch to save a little bit of time on 16 star.In whomp's fortress,when you need to climb up the staircase and avoid the twomps,you can easily skip it.Now,i don't know if it happens on the original N64 because I tested it in Nintendo switch.Next to the staircase there is a slope,right?Well,to skip the twomps,you can climp up a bit and land on the next step.That can be done on both twombs.