By acceptable, do you mean happier? Because this show started to get depressing after:
Spoilers
that incident with Suzuhara
End
And I can't see it getting any better.
Kinda, mostly just because it's a real ending and not whatever the hell they did.
I don't know if this would be a spoiler or not, but just in case:
It gets slightly happier, for the sole purpose of getting more depressing as it nears the dreaded final two episodes