Looks good, but only the 2nd tutorial worked and after clicking the intro texts away, nothing happens at the first graphic. Nothing I do with the keyboard or mouse causes a change. The 2 symbols are rotating. Is there a problem with the current version? Hope you continue with it.

Yes, they are meant to be difficult to pick out of the background at first - that is in keeping with their "shy" character (especially if one respons and the other is looking to eat it again!) and gives a bit of an advantage to the player who learns to spot them. I actually thought of naming one of them "Waldo", but that's another game. What do you think of highlighting them for a few frames - just enough to clue the players in?