I hate it when a series is only known for one game and thus the name of the series ONLY means that singular game and thus that's confusing.
Nier doesn't mean Nier, it means Nier Automatic Tomatoes.
Momodora doesn't mean Momodora, or Momodora 2, or even Momoora 3. No, it only means Momodora: Reverie Under Moonlight.
etc.