Added:

• Social Media Button (Itch, Youtube, Instagram, Twitter)
• Splash Image (my logo) at the start of the game
• Sunshafts at the start area
• 'Drag' to the rigidbody of the submarine
• Black fade in at the beginning of the game

Changes:

• Removed unnecessary gameObjects
• Set most gameObjects to static
• Rearranged the controls-menu