Developer 1st made the XenoGear game with interesting story, however due to lack of time and funding, the last chapter was cut short with story telling. This original version was too hard for me, and end up using cheat codes to pass the later chapters.
After switching to another company, developer renamed it to XenoSaga of the trilogy series; due to low sales, no more episodes are made. The story is deep and translation had to be renamed for global release due to sensitivity of the masses in their religious believes.
Overall, I think the 2nd episode is the best of the three
Sad to see no more episodes.