Honestly I wasn't expecting the ending to be like this.
It's hardly what I'll call a downer ending, but a sweet bittersweet ending. I like that humanity is still out there and maybe there is a chance for them to adapt right back to Earth
Also I love how they gave us one last glorious spergout for Yachiyo.
I loved this anime and it's only barely beated by Ninkoro for AOTS by a very small margin.
I'll happily buy that blu ray when it comes out