If you are interested, I say play it. It's not completely necessary or anything but there is something I really like about the original. I feel like it's a place hardly anyone in the world has been
I enjoyed it. Keep in mind, it was designed for an arcade controller. I feel it's a bit stiff and hard to play with a traditional controller versus stick. Otherwise, both DOA1 and ++ and very enjoyable experiences. It's fascinating seeing how much of the game has changed and how much has stayed the same.