First of all, notice Medusa and the tree to her left, and collect just the leftmost Heart, that has two Magic Shots. Shot the Snakey to the left of Medusa, and push the egg so to block her view to the left. Collect the other two Hearts in the lower part of the room, thus activating the Hammer power.
Walk across the jewel box, shoot the Snakey and push it up. Use the Hammer power on the rightmost rock, and collect two Hearts behind Gol.
Collect all the remaining hearts.
Get back on the arrows. In order to safely get the jewel, step half-tile down, so that Gol shoots a fireball, and retreat; as soon as that fireball passes by, run to the jewel box.
Consider the lower trio of Emeralds. Leave the left one untouched; push the rightmost one up two tiles and against the Medusa to the right. Push the middle one up against the jewel box, one tile left, then up and left against the Medusa.
Now the upper trio of Emeralds. Pust the rightmost one up against the rightmost Medusa. Push the left one up two tiles, then right against the rock. Push the third one down against the jewel box, right one tile, down to the level of the grass, then left against the rock.
Collect the two external Hearts first (near the Gols), then the two internal ones (near the Medusas). Grab the jewel and leave.
Take the three hearts in the upper-left area for four Magic Shots.
Push the upper Emerald one tile to the right. Push the middle one up one tile. Push the rightmost one all the way to the right and up to block one Medusa's view. Push another Emerald up (and right if necessary) to block the second Medusa's view to the left.
Bring Lolo next to Snakey, and turn left half tile. Shoot away two Leepers. Enemy hole: they will reappear between the Medusas and the Hearts. Collect those two hearts.
Push the leftmost Emerald to the left until one tile away from the wall, then all the way down. Collect the last Heart.
Use the Hammer power on the rock next to Snakey, get the jewel from the box, then leave.
Push the Emerald just below Lolo down one tile. Push the leftmost Emerald nearby left and down so to block Medusa's view to the right. Push the third Emerald up and left on the lower one-way tile so that Skulls will be unable to pass to the left. Push the fourth Emerald up between the Heart and Medusa. Grab the two Hearts.
Push any one Emerald down and left on the one-way tile. Push the upper-left Emerald left two tiles, then down and block Medusa's view to the left. Grab three Hearts.
Push one of the remaining upper-right Emeralds until it is below the jewel box, then down all the way, right and down next to the lower Medusa. WAIT before grabbing the last Hearts.
Push the last upper-right Emerald through the passage, then walk around it and push it back so to block the access to the left part of the room. Collect now the last two Hearts, grab the jewel, and exit.