Your task is in the vast cosmic space in Planet Buster- the destruction of the planets. They apparently provided for a similar perspective, so they built multilayer protection around the perimeter. It needs to be broken and you will use all the available arsenal. It is located below on horizontal panels and in most of it is still under the castle. To unlock access, you need to actively fire the planet with rockets, buy various improvements and expand the arsenal at Planet Buster.
