Level 4 is accessed with the password BZZY.
- Walk up to the lower of the two Emerald Frames to the left of the entrance. Push it two spaces to the left when the left Don Medusa is moving up and about to hit the wall. Then push the remaining Emerald Frame up half of a space. Collect the two nearby Heart Frames.
- Watch the Don Medusa along the top, and walk to the right while it is headed back into the upper left corner. Walk above the right-most of the two Emerald Frames on the bottom, and push it down when the bottom Don Medusa is moving left and about to hit the wall. Then push the other Emerald Frame to the left half of a space. Collect the two nearby Heart Frames.
- Use the same strategy outlined above to similarly trap the right Don Medusa, and then the top Don Medusa until all Heart Frames are collected, and the collect the key to escape.
- Collect the three obtainable Heart Frames near the bottom of the room (you'll get two egg shots), and then cross either sandy path to either of the upper Snakeys.
- Face the one of the Snakeys, shoot it once, push the egg into the water, and hop on the egg. It will float down the channel between the two islands. As it does, get off on one side, collect the Heart Frame on that island, and then cross back over to the other island to collect the other Heart Frame. Then hop back on the egg to continue riding it.
- The egg will stop above the final Heart Frame. Get off the egg and collect the frame. Then shoot the Snakey below twice to remove it from the screen and collect the key.
You must do some prep work before you attempt to collect the lone Heart Frame, or you will never reach the key alive.
- Start by heading over to the trio of Emerald Frames on the right. Push the top and bottom frames to the right, then push the middle frame down. Push the top frame up beneath the right Gol, and push the bottom frame down above the Medusa. Push the Emerald Frame just above you to the left to block the Gol above the chest.
- Return to the alley with the Gol at the bottom, and push the Emerald Frame to the left. Then walk around to get underneath it, and push it up at least one space to block the Skull's route to the right. Walk to the left wall, and push the left Emerald Frame to the right to block the Skull route below and confine it.
- Now collect the Heart Frame and make your way back to the key. The only potential danger you face is the Gol at the bottom of the screen, who will spit a fireball at you when you enter his line of sight. Just walk up and move to the right as quickly as you can before the fireball can touch you.
- Start by walking up to the Emerald Frame above you. Watch the Don Medusa above, and when it's safe, push the Emerald Frame two spaces to the right. When the Don Medusa is on its way to the left, run down and collect the Heart Frame in the lower right corner, and then return under the Emerald Frame.
- Wait for the Don Medusa to head back to the left again, and push the frame to the right two spaces until its under the bridge. Then push it up six spaces. Grab the Heart Frame to your right when it's safe to do so, and then wait for the Don Medusa to touch the right wall before pushing the Emerald Frame up one more space and pinning him into the corner.
- Head left to collect the Heart Frame above the Skull. This will activate the Ladder power.
- Use the Ladder power on the water to the right of the Skull, then cross over and head down to the last Heart Frame. Collect it, and immediately shoot the Gol to your right with an egg shot. Push it left as you approach the key. You should be able to collect it with plenty of time before the Skulls get close enough to catch you.
- Walk up the right wall, and push the left Emerald Frame up two spaces. Collect the Heart Frame in the upper right corner for two egg shots.
- Come down to the two Snakeys on the right. Shoot one once and push it left and up below the Don Medusa. Come back and shoot the other one once and push it further left and up below the Medusa. The eggs don't have to end up touching either enemy, they just need to block their view of you as you cross along the bottom. Collect the center Heart Frame.
- Walk up the left wall, and push the right Emerald Frame up two spaces. Collect the Heart Frame in the upper left corner. Then return down for the key.