Release of the beta v0.3

Releasing now the alpha version of the game (v 0.3)

I've reworked the game from the beginning and added many features like: 
-Main menu (with settings menu too)
-Pause menu
-FPS counter
-Made an animated backgroung for the menu
-Redesigned all the sprites
-Made the first working gamemode (Arcade mode)
-Added difficulty selector
-Added score and highscore counters
-Powerups will be dropped by zombies when dead
-Implemented blood effects
-Implemented firing effect
-Changed the cursor

The next update (v 0.4) is planned for the 2022/08/21 and planning to add features to the already existing gamemode.