Nothing more than a distress signal, neither good nor bad (2-2)
I believe the answer is:
so-so
'neither good nor bad' is the definition.
(I've seen this before)
'nothing more than a distress signal' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'more than' means one lot of letters go next to another.
'a distress signal' becomes 'sos' (SOS is an example).
'o' after 'sos' is 'SO-SO'.
(Other definitions for so-so that I've seen before include "Rather middling" , "Of middling quality" , "Fair to middling" , "'Passable, middling (2-2)'" , "Of average quality" .)