It was an okay Ending. Although should've had the fight scene longer(I had hope Layfon would atleast cut off an Arm or something other then sent the attack back.).
A shame that they took HB back, it would've been very useful for Zuellni if Layfon kept it to fight against FM.
To me they left it in an Open-Ending. Everyone went back to a normal lifestyle. There wasn't any real romance part in the ending (From my view, people are just putting it that there was romance)
Spoiler for My View on the ending:
-Felli went back to either scanning/self-training? (I don't really know)
-Sharnid? Going out with two girls (Fan's of his I bet.)
-Harley working on DITE's
-Nina and Layfon on break with Zuellni in the Machinery workplace. (They did that since Eps 2)
-Leerin sending Letters to him. (Doing that for the most of the series)