The Cherry MX Blue is both a tactile and a clicky switch. You can both feel the tactile bump and hear the "click" that occurs when the activation point is hit. Unlike most other Cherry MX switches, the plunger consists of not one, but two parts: a blue plunger (that is connected to the key) and a white inner slider (which opens/closes the circuit). The movement of the inner slider is constrained by the blue plunger, which can pull the slider up or push it down. At rest, the inner slider is held by the leaf spring. The blue plunger does not push on the slider until close to the activation point. At the activation point, the blue plunger has pushed the white slider out of rest into a position where the force of the leaf spring on the slider's inclined plane will propel the slider towards the bottom. The leaf spring encounters no more resistance from the slider and closes the circuit. Because the blue plunger is no longer pushing on the white slider, the key resistance decreases sharply.
The "click" sound is made by the white slider hitting the bottom of the switch housing. The force of the leaf spring on the slider is high enough to make the switch function in any orientation.