1-3. In the middle there are the medium sized green ships (Before the Huge red one) that have lots of small green ships around them that fire pink triangles. Shoot the big ones till they are about to blown then stop firing. Once the screen is filled with pink arrows blow the big ship up and the pink triangle bullets are cancelled and the small ships are easy prey. Cancelling those bullets greatly increases your score (3-6 million) depending on how long you leave it.