Retro Jam - Day 2

Added the Egg mechanics today:

• Billy can kick the egg away
• Billy can do a ground pound while holding the egg in midair. This results in a large bounce, just like the original game
• The egg rotates organically as it moves
• Collision checks for horizontal and vertical movement, including the egg bouncing off of walls if kicked
• Egg grows as you roll over fruits. Once the egg is big enough, it'll be ready to hatch. Getting a kick out of how absurdly large it gets. Keeping it for the humor of it.