Added difficulty settings.
I plan on a fully customiazble difficulty configuration, but for the moment it is easy/medium/hard, medium being the setting from the versions before.

Added another buff: The Shrink buff.
This buff is purple and decreases the size of the player up to three times.
After this every collected shrink buff will add 10 points. Also, if you collect a shield buff while you already have a shield, now you also will get 10 points.

Finally some fine tuning of the movement rate increases of the enemies.

Added buffs to the game.
These appear in the form of green circles you should not dodge!
At the moment there is only one type of buff, the shiedl buff. When you collect it, your square will have a shield, meaning you can survive one enemy hit.

I plan to add more buff types in the future.