It's very annoying when it *doesn't* show! That is
not a good way of making the game challenging!
If the game needs something like that not to be too easy, then it means that somewhere, something went wrong. My guess goes for level designing. -. -.'
It's not a horrible game, but I think that it could use more creativity; I've seen enough of Drop Block clones, and most of these actually added something new and more interesting than lacking information about blocks destination. ^^'