Honestly, the biggest criticism of Dragon's Heaven I have is that there just isn't anything to it. It's a post-apocalyptic setting, but it boils down to a desert that is a featureless Tatooine (and that isn't the only thing that looks ripped off from Star Wars). Our protagonist is a cute, spunky, 80's anime girl, and the most important thing about her character is... hold on, I'm sure there was something... she takes a bath? She's out in the desert and wakes up a robot. The robot follows her home, and she decides to keep it. Now she and her pet robot become the only force to stop invaders, for some reason. They win and mecha-fido doesn't even have to die.
Then there is the art that rides the line between being highly detailed and being messy. A lot of the shading was done in the lineart, and sometimes without any color, so there might be times you only see four or five solid colors. There will also be times where a liberal airbrushing puts colors everywhere, so it ends up feeling like it's lacking coherent art direction. Did I mention the four minutes of filmed footage?
If you have started to exhaust all of 80's mecha anime, then give it a shot. Otherwise, no one is missing anything that hasn't been done better elsewhere.
