DK Jungle Climber

Collect the all oil barrels in the indicated level.

Then press X to have Funky fly you to the corresponding bonus level.

Little Chill 'n' Char Island: The five oil barrels in Chill 'n' Char Island.
Little Ghost Island: The five oil barrels on Ghost Island.
Little High High Island: Both oil barrels in Little High High Island.
Little Lost Island: The five oil barrels on Lost Island.
Little Sun Sun Island: The four oil barrels on Sun Sun Island.

Complete the main storyline with the indicated number of banana coins to unlock the corresponding bonus stage in the 'Extra' menu.

Stage 1 - 10 banana coins.
Stage 2 - 20 banana coins.
Stage 3 - 30 banana coins.
Stage 4 - 40 banana coins.
Stage 5 - 50 banana coins.
Stage 6 - 60 banana coins.
Stage 7 - 70 banana coins.
Stage 8 - 80 banana coins.
Stage 9 - 90 banana coins.
Stage 10 - 100 banana coins.
Stage 11 - All 105 banana coins.

Complete the indicated levels in the listed Challenge mini-game to unlock the corresponding bonus level.

Banana Grab level 2: Complete Banana Grab Level 1 with at least 80 bananas.
Banana Grab level 3: Complete Banana Grab Level 2 with at least 100 bananas.
Banana Grab Max (Survival mode): Complete Banana Grab Level 3 with at least 140 bananas.
Booster Battle level 2: Complete Booster Battle Level 1 by defeating Funky Kong.
Booster Battle level 3: Complete Booster Battle Level 2 by defeating Dixie Kong.
Booster Battle Max (Survival mode): Complete Booster Battle Level 3 by defeating Diddy Kong.
Orange Picker level 2: Complete Orange Picker Level 1 with 60 oranges in 30 seconds.
Orange Picker level 3: Complete Orange Picker Level 2 with 100 oranges in 30 seconds.
Orange Picker Max (Survival mode): Complete Orange Picker Level 3 with 130 oranges in 30 seconds.
Rolling Panic level 2: Complete Rolling Panic Level 1 with at least 100 points.
Rolling Panic level 3: Complete Rolling Panic Level 2 with at least 150 points.
Rolling Panic Max (survival Mode): Complete Rolling Panic Level 3 with at least 250 points.
Speed Climb level 2: Complete Speed Climb Level 1 within 15 seconds.
Speed Climb level 3: Complete Speed Climb Level 2 within 20 seconds.
Speed Climb Max (Survival mode): Complete Speed Climb Level 3 within 28 seconds.
Throw 'n' Crush level 2: Complete Throw 'n' Crush Level 1 within 40 seconds.
Throw 'n' Crush level 3: Complete Throw 'n' Crush Level 2 within 50 seconds.
Throw 'n' Crush Max (Survival mode): Complete Throw 'n' Crush Level 3 within 60 seconds.

Complete the indicated level to unlock the corresponding mini0game at the Challenge menu.

Banana Grab mini-game: Complete level 1-1 'Cranky's Teachin's'.
Booster Battle mini-game: Complete level 5-1 'Space A-Go-Go'.
Rolling Panic mini-game: Complete level 1-1 'Cranky's Teachin's'.
Speed Climb mini-game: Complete level 1-1 'Cranky's Teachin's'.
Throw 'n' Crush mini-game: Complete level 2-3 'Road To Ruins'.

Open the cheat menu by getting five DK coins. The cheat menu is in the "Extras" section.