Originally a tape for the Imagination Machine, this is the Best and Last cart made for the APF MP1000
A brilliant reproduction of Space Invaders
Although this cart is 1/3 taller than the other APF carts. Its the only one that fits the box without a spacer. APF must have originally intended to have many extended games, but this is the only one they released.
The top line is standard text mode, followed by 256x180 lines of high res graphics in 'Buff on Black' switching to 'Green on Black'* for the bases and tank.
For a discussion on how this screen layout is achieved see: VDG Tricks
Space Destroyers has 2 ROMs plus 1K ram in its cart.1013a ROM