Why are there clear-cut states of matter instead of a gradual transition from gas to solid?

Why are there clear-cut states of matter instead of a gradual transition from gas to solid (let’s set plasma aside for the purpose of this question)? If the main difference between them is the distance between molecules, then with temperature going down (let’s neglect pressure for the purpose of this question), a gaseous substance should gradually become more and more liquid and then more and more solid, shouldn’t it (as if God fiddles with a slider in his computer interface; let’s set aside the question of God’s existence for the purpose of this question)?