B3

The base is protected from the back and sides by mountains. On the front side, it has a wall with firing points. To protect the base, you need to move all around these points, using a teleport system. So, when you need to go to another point, you look at the flag above it and instantly teleport to the point.
Monsters appear from the side of the desert in random waves. They attack the wall. After the destruction of the wall, monsters penetrate the base. The game is over when the first monster reaches the control point inside the base. There will be several types of monsters and they will require different tactics to defeat them.