You'll rarely feel like you've had some cheap deaths. Most of the levels are a lot of fun to explore and play, even after several times. One of the biggest cheap deaths is in world 7, when you go up a pipe and a koopa can easily walk on you and kill you if you're small, or steal one of your power ups. You can't see it to avoid it, either. But, those situations are really, really rare in this game. At the same time, it's challenging and is difficult in a fair way that makes you feel like you accomplished something when you clear a tough level. And the levels at the end of the game definitely grow difficult.
June 26th, 2016