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' (O resembles 0).
'more than' means one lot of letters go next to another.
'a distress signal' becomes 'sos' (SOS is an example).
'o' put 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" .)