[skeaker]

There are a couple of mechanics that can only be observed on a fully visible board (the death screen), such as the purple slime mage who is level 1 but is always surrounded by level 8 tiles or the basilisk that marks number tiles with a ? in a diamond shape.

[Livanskoy]

Minor correction: it's a beholder, not a basilisk. Look them up, they're adorable.