I recently read Hot House, also known as The Long Afternoon of Earth, by Brian Wilson Aldiss. As mentioned in the interview linked from this topic, the novel was the first basic inspiration for the Panzer Dragoon series. I can definitely see the influence.
The world reminds me a lot of Panzer Dragoon. Humans (or rather their evolutionary descendants) are at the bottom of the food chain. Instead of monsters, the world is filled with carnivorous plants. Life is short and harsh.