The monsters can move in a serpentine or straight forward fashion.
In addition, you can select from multiple difficulties which decides how fast the monsters move and how strong they are.
Although there is only 3 difficulties, you can mix them together to create harder challenges (a total of 7 difficulties if you look at it this way... example: you can spawn the Easy and Medium waves spawning at the same time).
Be warned though... activating all 3 difficulties at once will be very difficult.
Rules
1) Play on adventure
2) No cheating
3) Difficulty: Normal or Hard
4) Render Distance 11+
5) Play by yourself or with friends
6) Have Fun!
Note: If you are playing in multiplayer, please make sure command blocks are enabled!
Challenges
1) Defeat all 7 difficulties (Easy, Medium, Hard, Easy Medium, Easy Hard, Medium Hard and Chaos)