Main Menu 2.0

We updated the main menu with options and credits.

You can now Change the resolution and the screen mode in the optiones. Also you can see the team leading this project in "Credits"

Also, you can exit the game whenever you like with "Esc"

A Pause menu is in the making.

Minor bug fixes:

•  Added Shooting cooldown based on "Attack speed"
•  Modified chance to spawn item on enemy assasination