Lag

If you use "Tunnelers' Dream" in about 10 to 15 seconds it starts lagging and then it stops responding.

Tunnelers' Dream won't responding

If you go to creative game mode, superflat, clicking on customize, use presents "Tunnelers' Dream", once you use that world to play with, about 10 to 15 seconds it starts lagging and when trying to exit/close it, the application won't respond that you will force quit the app.