Version 2

- Added game end screen
- displays:
- score
- difficulty
- button to move onto next difficulty if level completed
- button to return to main menu
- Added difficulties: easy, medium, hard
- As difficulty increases:
- Player is invulnerable less time after being hit
- Player cannot attack for as long between charges
- More enemies appear
- Enemies do more damage
- Enemies fire faster
- Enemy bullet speeds increase
- Enemies can see player from farther away
- To come: difficulty levels will change the location
- Added charge bar below player
- displays current charge percentage of attack
- Added score bonuses:
- bonus for completing level
- bonus for completing level without taking damage
- bonus for completing level without attacking
- more to come...
- Enemy pictures updated
- change colour when player is in line of sight and attackable
- Dozens of constants added to make for better/easier code
- Changed enemy start positions so that they are scalable depending on:
- number of enemies
- size of background
- constants declared at start of code
- Changed some button functionality and positions
- Fixed player attack distance so it's equal left and right