From Lylat Wiki, your source on Star Fox information. By Fans, for Fans.
Fox pushing a stone block in the Gas Trap
The Gas Trap is a room in Cape Claw in Star Fox Adventures. Fox can enter it once he retrieves all four Gold Bars for the HighTop.
Fox enters this room unsuspectingly. There is a tall column in the middle of the room, and surrounding it are four stone blocks, placed at right angles from each other. After finding that none of the blocks would budge, Fox tries to leave the Gas Trap, only to have the door close shut in front of him. The four blocks slide backwards and into corners of a track on the ground, revealing vents underneath. Poisonous gas emerges from the vents and starts to fill up the room. Because of this, Fox has limited time to reopen the door and get rid of the poisonous air. He can do this by sliding each of the four stone blocks back onto their respective vent. Once the door to the Gas Trap reopens, the grating that the Queen CloudRunner is imprisoned behind sinks into the floor, freeing her from captivity.