Hey KannonBoom try clicking on the sprite from the project panel on the right and then on the left panel check to make sure your opacity isn't 0% and the box that says initially visible is checked off. A couple of other things to check are Z order and sprite movement. If you have a background or other object it may be showing in front of your blocks right click the block and check the z order bar. If your blocks have movement like a bullet behavior it could just be flying off the screen. I'll attach a couple photos. Hope this helps.