In order to get an overall SSS rank on a stage, you must get SSS in all three graded areas (time, hit points, and score). For the HP stat, you CANNOT get hit in order to get SSS.
Time varies from stage and difficulty, and you will be able to see your score progress as you go trough the stage.
I figured this would be a hard level to get SSS on, but it turns out it was by far the easiest.
You will want Swords and a shield. That is all.
You will want to do this on easy and must be pretty good and dodging the swinging hands.
The shield is used to protect yourself from projectiles (to keep your score from dwindling too much, hold the shield in front of you and use your other hand to swing in front of it. This will give you some score back from destroying rocks).
You will wait for the giant to swing down and you will need to sidestep. Once his hand is near the ground, swing like crazy with duel wielded swords and you will do tons of damage and get a bunch of score multipliers.
Once both hands are destroyed, the giant will do a headbutt attack. Crouch down and away when his head comes down and swing upwards with a sword. This should stun him and he will fall. Now, go nuts with the swords to his chest.
Rinse and repeat.
Remember, DON"T GET HIT.
When he is 99% of the way dead, he will shoot a constant barrage of rocks at you. Just hold your shield up and swing at the rocks with your sword. The giant will eventually walk right up to you and you can swing the killing blow.
Using the above method, the time and score shouldn't be an issue.
Good Luck!