Shall I be evil and tell LD the easy way to do the last jump for the wallkicking snow level star?
...
Yes

Instead of making a nasty running triple jump to the far wall then wallkicking back across, you'll note the top ledge is a bit to the right of the edge of the lower ledge. I just do a flip around high jump to get decent height, then wallkick towards the screen. Provided you're going slightly right when you do this, you land on that top platform.
After you've done Mario, I'd highly recommend Banjo Kazooie for more cutesy 3D platforming fun, or Conker's if you want to play something more adult. Just a shame the only "sequel" to Mario 64 was Yoshi's Story, which was really a sequel to the SNES' classic Yoshi's Island.