Much like MGS2 :Sons of liberty, you can change the background when you first start the game. Try the following:

Press R3 to change the color of the background.

Press L3 to change the pattern of the background.

Press R1 to speed up the CQC scenes.

Press R2 to slow down the CQC scenes.

Use L1 and L2 to change the color of snake and the enemy.

And press Triangle to reverse the color of snake and the enemy.