Very beautiful and interesting ball waiting for you in with it you will be able to test their reaction, as well as improve it with deviations from the falling blocks with the top! Try not to go far for half a block, what in case you have time to re-fall time to step aside, and you are not hooked block! You will not be much chance of error, but you should use them very convenient, because more will be more difficult, but we can not be wrong!