You can collect the Heart Frames in any order, but you do have to be careful about avoiding the Rockys. Touching them is fine, but you don't want to end up trapped in a location you can't escape from. In general, it's safer to start by collecting the farthest Heart Frame, and work your way back to the treasure chest than the other way around.
Push the Emerald Frame on your left to the left above the right Skull. Push the frame on your right over to the right wall. Then stand above it and push it down into the lower right corner of the room. Come back up, and push the frame to the right of the right skull over to the left, giving you access to the treasure chest.
Collect the Heart Frame along the bottom wall, and then come up to collect the frame below the left Skull. While you're there, push the neighboring Emerald Frame to the right below the right skull.
Come back down, collect the Heart Frame between the two Emerald Frames, and then work your way around the outer edge of the room to collect the last two Heart Frames along the top wall. Push the Emerald Frame below you down so that you can access the path to the key. You should get there in plenty of time before the left Skull even finds a way to reach you.
Walk to the lower left corner of the room. Push the two outside Emerald Frames up one space, and push the center frame to the left. Collect the Heart Frame above. Then do the same for the three Emerald Frames above, giving you access to the chest, as well as the two Heart Frames on either side, which you should collect.
Collect the two Heart Frames on the right half of the room, and then approach the Heart Frame that is keeping the Alma trapped in the upper left corner of the room. Wait for the Alma to walk away from the Heart Frame. When it walks up, collect the frame, and walk to the left until you are above the gap in the trees.
Wait for the Alma to roll into a ball and chase you to the right. Then duck down between the trees and head straight for the key.
Walk up to the chest, and push both frames out one space towards the trees. Stand below the left one and push it up four spaces so that it sits to the left of the Medusa.
Come back down and walk up along the left wall to collect the three Heart Frames on the left. Then push the left frame one space to the right, closer to the Medusa.
Walk back down and repeat the same steps on the right side. Then collect the key.
The Don Medusa here moves up and down. When he's on his way up, walk up to the lowest Heart Frame on the right side. Collect the heart, and then walk around to the opposite side of the Emerald Frame that you're standing next to.
Prepare to push that Emerald Frame to the left when the Don Medusa passes below it. Then push the frame down above him so that he is pinned against the wall.
Now collect all the other Heart Frames, but before you collect the key, push any other Emerald Frame down to the left of the Don Medusa so that he doesn't shoot you when you grab the key.
