2D Platformer

This is 2D Platformer project.

• Added Gravity inverting pickup -- Apple
• Added Gravity update script -- ApplePickup.cs
• Player flips the sprite accoridng to gravity mode.
• Modified walking enemies prefab to work in gravity inverted mode.
• Two levels are created.
• First level is with modified UI as given in modification examples.
• Second level is almost same as tutorial videos.