W is up
S is Down on mine
(dunno if i set them to inverted back when i installed the game 2 yrs ago ..so check your settings in game )
those levels can be tough ..make sure you just tap your Keys , rather then hold them down is a good tip !
in those levels you have to fly to the red rising leaves to gain altitude ..i kept holding my Keys down and smacking into the rocks till i learned to tap my keys just right .
tap your C key to land and stop flying ..if ya need to land on a ledge or cliff