Originally Posted by Sergorn
There's no mention of any Ultima relation so I would assume this was not an Ultima. Though I guess we'd need to ask someone who worked on it to be sure.
I haven't heard anything about Serpent Isle selling poorly actually. I could see it selling less, but it was still considered a core Ultima and was popular (unlike the WoUs), and with it based on UVII's technology it probably cost a lot more to produce.