DKC Warp

Detailed explanation:

1:00 After re-entering the level, throw the DK barrel to start and select out. The game is now tricked into thinking that the DK barrel was destroyed and that you have Diddy with you as the second character.

1:03 If you press a button in the corner between the first two levels (requires you to have one character on the map screen, the timing is frame perfect and does not work with all revisions of the game) you are able to warp into level 3-5.

1:08 When damaged, you are supposed to play as Diddy. If you would take damage on the ground, Donkey will stay frozen and softlocking the game, as there is no Diddy to take his place. But dying above a whole will kill off Donkey.

1:46 If you stop riding the barrel above an animal friend, and keep holding Y, it's possible to ride with the barrel. You can then destroy the barrel by jumping in a midway barrel. The barrel is destroyed, but the game is still expecting that you hold something. What's happening here is that you are now holding the next sprite that is spawned in memory, which can be an enemy, another barrel, a bonus etc.

2:03 He releases Y to throw the barrel, this will "activate" the sprite he was holding, in this case the bonus entrance. Because sprites aren't supposed to be controlled this way, strange things happen. In this case, it will change the exit value of where the bonus will take you after you finish it.

2:10 Breaking the DK barrel will get Diddy back and activate a glitch called "Split up". While the effect is too short to notice here, you are basically able to control both characters at the same time, instead of one following the other. As Donkey is technically dead, Diddy will become the active character and the one that the camera will focus on. The fake character, Donkey, is unable to die and interact with certain objects. Right at the moment when Diddy gets out from the barrel, both characters are however considered active for one frame. You'll have to exit the bonus with the both characters on this frame and the exit value will be changed once again. Runners try to line up on an exact pixel in order for the glitch to work. If you are two early or late, the game will either crash or warp you to a different location. As Donkey is still dead, he disappears and Diddy will be riding Expresso instead.

If you have further questions, go on =).