Most animations on scratch are laggy because its costumes change quicker than the cache can load them. So i made a cache preloader for this proyect (cache preloaders depend on the type of proyect,animation,sprites,etc... so they are not fully compatible with other proyects). The logic of its working is quite simple: ·You load quickly all the costumes (by forcing the proyect to change to all the costumes). ·You make the loading be executed when the greenflag is pressed,not the animation.The animation must be triggered after the loading has been made,usually i use a "send message" block to trigger them. ·You can hide it if you want,my personal fauvorite for sprites is to make them completely transparent and for backdrops to make them completely dark (using the visual effects that scratch blocks have).