Quick QOL update changes

Already managed to gather some feedback and decided to throw few quick fixes before my last exams!
Wish me luck on tuesday and friday and I'm leaving here a list of changes and going back to study.

I hope the game will feel a lot smoother right now (the play again button still doesn't work tho :x)

- Now can hold to move

- Fire AOE increased

- Score counts properly

- Spell has small cooldown

- Difficulty adjusted