Password: BBLS
First, have Olaf and Baleog climb the ladder to take out the enemies there, and then have them climb the next ladder and do the same so you can get the items. Now all three vikings must navigate across the pool by falling from bubble to bubble. Start on the middle level and keep an eye on the bubbles below each viking as he crosses. Just aim for the next bubble below and to the right and it shouldn't be a problem. Once all three vikings are across, have Olaf climb the ladder and stand next to the red keyhole with his shield above his head, so Erik can use the shield to reach the ledge above. The red key is easy for Erik to reach, but before he uses it make sure to have Olaf hold his shield in front of him to protect them from the red lizard on the other side of the door. Have Baleog destroy the red lizard, then have Olaf climb the ladders to block the blue lizard so Baleog can destroy it, too. Above the next ladder are two more enemies that Olaf and Baleog have to take care of before Erik can safely catch up. Now, have Erik climb up the ladders to where Olaf and Baleog are, and he can reach the fruit on the left. Also, he can jump to the ledge with the red lizard and get the smart bomb. Just jump over the red lizard to avoid getting hurt, and have Erik rendezvous with the others again. Now have all three vikings go to the left where the ladder is, and have Olaf climb first so he and Baleog can do their thing. Now Erik can climb the ladder and reach the gold key. Have Erik continue to the right and use the smart bomb to take out the red lizard on the other ledge. Now all three vikings can fall to this ledge and continue to the right, where there is a door with a gold keyhole. Olaf must again use his shield as a platform so Erik can jump over and use the gold key to open the door. Once the door is open, Olaf and Baleog need to walk to the right to clear the path of enemies so all three vikings can reach the exit.