Berserk 2048 (4096 (...))

How to play:
Swipe the cubes(right, up, down, left) to merge 2 identical cubes. There exist deterministic way when they will not merge(difference from classic 2048). This is not disadvantage or advantage. It is just speciality: when 2 cubes are beside and moving 3 squares they will not merge!
Second speciality is berserk. When berserk appears you can change cubes with values 2, 4 or 8 to 4, 8, 16 but only one of them. Berserk will disepeare after you will use it or after few swipes.

Easy mode - 2048
Medium mode - 4096
Hard mode ...
NIGHTMARE - 16384