That's not really a fair comparison. The Atari didn't have any video memory, you drew by changing the color of the electron beam while it scanned the screen. It

That's not really a fair comparison. The Atari didn't have any video memory, you drew by changing the color of the electron beam while it scanned the screen. It also had only 16 colors and a much lower resolution than what's being used here (maximum was 160x192 if you really tried). In comparison, this game uses 320x200 with 256 colors (using 64k of video RAM). To draw a pixel on the screen, you just write a byte to the appropriate memory address. Still, it's pretty impressive to write space invaders in only 512 bytes.