Using Aesprite i have animated the blade and exported it as a sprite sheet and imported this into unity and made it into a prefab.
Making Blade Move
the game has a Blade Spwaner logic that will spawn the blade after the player has gone to a certain distance down the level. Blade Spwaner takes in the prefab for the saw blade as well as the start location as public variables. the start location is an empty game object in the scene that scrolls with the camera.
This code will spawn a vertical and horizontal moving blade, the rate of spawning each type is 50%, the two Boolean flag will trigger the spwanning logic for either of the two. the hasSpawn variable is to make sure only one is spawned at any given time
below is the the logic for the blade it self, this moves the blade in the game at a certain speed and destroys it self after it has left the visible area after 5 seconds. in unity if an object leaves the camera viewable area the IsVisible property of the renderer returns false, so here both this boolean flag and the Timer is checked.
Thanh Hon 