Visual update & meta progression

What's new?
Changes 

• Many visual changes (doors, backgrounds, assets, effects, skills, ...) 
• New main menu music
• New meta progression for the hub NPCs
• Added teleporters from far away side paths back to the main path 
• Better tutorial informations 
• Added option to disable the screenshake 
• Many bugfixes 

Balancing 

• Enemies have more HP now 
• After a level you will face the boss and not another 1-2 level