While this game certainly doesn't suck, I found it to be disappointing. When I saw a commercial for the Intellivision version of this game, the game included a mothership. I expected the Atari 2600 version to also have the mothership but it didn't. That was very disappointing. I actually felt like I had been cheated when I bought and played this game in 1984.
About fifteen years ago, I also bought the Atari 800 version of Demon Attack but it doesn't have the mothership either. The most likely reason why it wasn't included in the Atari 2600/800 versions was because Atari sued Imagic. For those who don't know, Atari sued Imagic because Demon Attack was similar to the Atari 2600 version of Phoenix.
If this game had included the mothership, it would've been so cool. But because there was no mothership, I felt let down. Can you imagine how people would've felt if the mothership hadn't been included on the Atari 2600 version of Phoenix? That's how I felt when I played the Atari 2600 Demon Attack.