Once you are in a mine cart, be ready to jump as you head down a hill through some bananas. You must jump early so you can hit the small patch of track. From there, jump up to get the K KONG letter.
After ducking under some low crystals, get ready to jump onto a Mole Guard in a mine cart coming at you. As soon as you hit him, jump again to get a boost up to the top track. From there, you can get some bananas and then jump across to a short track with a Puzzle Piece.
Stay low as you go under more crystals. You must jump over a couple obstacles, then duck down. As you exit this area, be ready to jump so you can get the O KONG letter and cross the gap to another set of tracks.
To cross this gap, perform a low jump with just a tap of the jump button. You want to land on the lower track so you can get the Puzzle Piece. Then quickly jump to the higher track so you don’t fall off the end.
When you see this sign with an arrow pointing down, don’t jump across to the next track. Instead, let your cart fall off the edge. It will land on a lower track you can’t see until you fall. Ride it to get the next Puzzle Piece, and then immediately jump back up to the higher track before you fall off the edge.
After the checkpoint, you must duck down as crystals drop and then jump over a Mole Guard in a cart. As you go past bananas, get the Puzzle Piece and then quickly duck down to get under another dropping crystal.
You will reach a section of track where there are five Mole Guards riding in carts in the same direction as you. Perform a low jump onto the first Mole Guard and then onto the second one so you don’t hit the low ceiling. However, really jump for height off the fourth Mole Guard so you can get the N KONG letter before you fly past it.
The Mole Guards will try to stop you by blowing up the track in front of you. Just jump over the gaps and keep going. Eventually you come to a very curved piece of track that breaks off and acts like a wheel. As you get to the opening, jump so you don’t fall. You can grab the G KONG letter during one of these jumps.
Once you reach the Slot-Machine Barrel, run past it and roll into the cave on the far right side. Enter a bonus area where you must do a lot of jumping between stationary platforms to collect several bananas and a couple coins. After you get them all, you earn the last Puzzle Piece.