First beat all the difficulties with first place on Normal, Hard, and Expert. Then you will be able to get a giant penguin practice mode. Contributed by: [email protected]
On stunt mode, go to Glacier Coast. Go to the huge (ice burg) or (the ice). Here you can get tons of points. Turn right, and when you get close the water, do a flip (push up, and then down) and hold down. If you do about 5 flips you will get at least: 2000 points. If you get very good at it you can get a maximum of 9999 points. If you here Cooool! or another comment you will get no points at all. If you do 10 or more flips that will happen to you. This code given by Stuart Spence.
In Championship Mode on Southern Island get 35 points, and on your second lap a killer whale will follow you. Get 45 points (by playing Expert or Reverse Difficulty) and the Mario 64 Penquin will follow you.
Hold Up while selecting your players.
On the Dolphin Park Stunt Mode, do a dive at the first jump. Then pause the game. Unpause and do no-aeriel stunts, passing each checkpoint with only a couple seconds left, and you should have a huge score.
In Dolphin Park Stunt Mode do every single stunt and go through all the rings. If you did it right you should here a dolphin sound. Now while choosing you chacter hold Down.
Score First Place in all of the other difficulties and now you will be able to play Reverse Mode.
In Southern Island set the waves at calm in the options menu and take Miles Jetter (maybe possible with others but hes best for it) set it so its pretty fast but not that heavy or slow acceleration. You can only do this first lap so when you pass the buoys after the sunken boat line up down the center and don't forget to keep max power and hit the jump from the bottom left and go off the top right. Aim for the spot between the two huts and pull back a bit. It takes some practice but once your better you can pull off barrel rolls over it too.