StarTropics 2: Zoda's Revenge

Hint: Desert level: Hidden tunnel:
There is a cactus with one arm facing down, rather than both arms up like all the others. Face the cactus above the one with the arm down from the left. Then, turn left and walk until you hit the wall. There is a tunnel there that you need to go through to continue.
Information in this section was contributed by Zac.

Hint: Haunted House level: Defeating the ghosts:
You must shoot the ghost that is the whitest to kill them all. Look carefully to find it.
Information in this section was contributed by Zac.

Hint: Chapter 9 level: Trail choice:
You will reach a room with three different trails to choose from that have the speed arrows. Select the bottom trail as it has more Medicines. This will help when you fight the final monsters.
Information in this section was contributed by Zac.

Hint: Caveman level: Exiting cave:
You will reach a room with three different ways to go. Each way has a shape. Follow the shapes through the rooms in this order: circle, circle, triangle, square, circle, square, triangle. That will get you out of the cave to continue the game.
Information in this section was contributed by Zac.