Get rid of F3 and F4 jumping possibilities.
The game will now start in menu again.
Temporarily comment out setting gamestate to STATE_PLAYING when gaining focus because it gives a lot of false results.
The collision detection between enemies and players is now properly working again and you now properly bounce into the right direction when a collision happens between a player and an enemy.
Players now lose one of their lifes when moving into an enemy.
The background of the menu is now properly black again.