There can definitely be play in any hinge with use - it's like your front door
But that won't affect the use if the lid is in the same place each time you stamp.
But if you watch the video, you'll see that if you just let the MISTI work, and don't pull the lid in one direction or the other, your image will always be in the same place.
However, if you find you like to pull the lid down towards you as you close it, then just be sure you always do that when you stamp. If you are a pusher or a puller, just be sure your motion is consistent every time and your image will be perfect.
Also, be sure your cardstock is always in the corner - I can't tell you how many times I have gotten careless and let it move a bit