Run score might be the most confusing part of the end screen, so i decided to explain it here. You can get points by:

• Defeating Evil Frog(always 1000 points)
• Beating the game as fast as possible(5000 points for every time below 30 minutes)
• Low Turns Taken(2000 points for less than 200 turns)
• Not loosing Hp(2000 points for 20 lowest hp)

So the priority in the Fullscore% is not loosing health and not speed. Hope it helps.