How do I get to the rune in Forgotten Island?

It is in the area with lava when you must choose which dead lava monster path to use to get across. Go right and jump on the tall stone sticking out of the lava. Step on the button and guide your boomy through a tunnel to open a locked door. Continue through until you get to a wolfen and a cannon. Defeat the wolfen and use the cannon to destroy the rock barricade. Jump to the crates and get off at the end. Repeat. This will go on forever until you finnaly reach the rune.

After using an air cannon to land on a mushroom,you'll notice when you 1st get
There,there is a circle of mana balls below.Behind you is the rune. Use your boomy to press the green switch and it will open the gate.When you have to go and fight the wolfens,you can escape out the open gate and recharge yourself with the amber block and get the rune.The wolfen won't follow you out here,and even if you fall into the lava and have to start over,the gate will still be open!