I will move this post here as it is where I actually meant it to go when I accidentally posted it in the H16 thread...
This level often needs a lot of luck. If you get lucky the enemies on each side will block themselves in for a few turns. As you will see, I didnt get particularly lucky today but this is the way I got three stars...
Turn 1: Move right and quick shot the Rock Pelter. If you dont get at least one critical I would start again (although your Crystal will have higher power).

Turn 2: Do whatever you need in order to take out the Rock Pelter. Do not Quick Shot or Ice Drop if it will result in you hitting the Purple Sword. I only ever use flame of triple power attack on this. If you are aiming for three stars if either the far left or far right dragon has a shot at you at this point start again.

Turn 3: By now the Eggy on the left will be free. You will have dropped down a bit and he is likely to hit the Rock Pelter. Quick Shot at the Rock Pelter and take him out. This turn I used my rage and killed him in two of the shots. I had lined it up so that the third will hit the Eggy.

Turn 4: You will notice I made a bad shot on this turn. The idea being to kill the Eggy, whereas I accidentally knocked him forward and wasted the turn. I wasn't aiming for three stars so kept playing.

Turn 5: Shoot so that you get the Health boost. I have noticed a trend in Laputa that the more power that goes into a shot that hits a health boost the stronger the boost (ie. Don't use a Quick Shot or Volley if you can triple power with a regular shot). In this case, I used Grenade as the risk of me accidently dropping myself off the ledge is lower. The disadvantage of this is that it will also hit the -1000 coin (again I didnt care about that this time)

Turn 6: Move to hide from the shot from the fire shooter. The position in this screenshot is usually pretty safe.

Turn 7: Shoot at the Flame Magalon. It wont matter if you accidentally give him power as he shouldn't hit you regardless.

Turn 8: Finish him off. If you don't make the mistake I did and miss one of my shots or collect any of the -1000 coins you will finish the level in 7 turns and get the full 2,500 turn bonus and should pretty easily get 3 stars.
I hope this helps. It is only my strategy but I never have much trouble at least finishing the level with it. Obviously my health would be much higher if I hadn't have missed one of my shots and this would increase the score.