Update 0.6.7

1 - A lot of people asked me to lower the difficulty but the game became boring when you are not a beginner anymore.

So to fix that :
 -Before lvl 5 :
                Slower anomaly on easy and medium difficulty.
-After lvl 5 :
                Anomaly spawn rate will be like before on easy and medium difficulty.

Increased spawn rate on hard and nightmare difficulty.

2 - Sound effects and horrific events are now rarer to reinforce the surprise effect.