Zwei plays and looks better. The 1st game for me had the better Art direction, better music and end of level bosses. I also liked how the game captured the feeling of how it was just you and your pet against the whole world.
Brings back memories of me as a kid when I would be sent up to my room for being naughty and my faithful old dog would come in and lick me to death to try and cheer me up and where I knew my dog would give his life to save mine (like most dogs would tbf)
Panzer Dragoon captured the sense of companionship perfectly