From The TimeSplitters Wiki

Gone Bananas
IMAGE NEEDED
Game	TS2
Section	Banana Chomp
Map	N/A
Character	Private Coal
Enemies Encountered	N/A
Rewards	Private Coal
Medal Requirements	Bronze: 1 min 30 secs. Silver: 1 min. Gold: 55.0 secs Platinum: 45.0 secs

Strategy

Get really used to the layout of the level and try to work out a way to get around as fast as you can. If you get all the timings and movements right then you should be well on your way to the Platinum .