THIS IS NOT A GUIDE IT'S JUST A HELPFUL HINT TO HELP IN A BUG IN THE GAME.
Hi, guys this is just a warning on the IJN mission attacking Darwin the game seems bugged.
I had destroyed all the targets, aircraft, hangers, artillery etc but mission still had not ended. I was flying around bombing and shooting anything I thought might be possible target.
After becoming frustrated trying to find more targets I noticed there is an another unmarked airfield in the distance look out for the tall control tower.
The airfield has about six or so unmarked buildings. With no anti aircraft, artillery, aircraft etc.... just few buildings.
I bombed the buildings at the airfield any thankfully mission ended.
It seems the developers have forgotten to add the markers for this airstrip.
Hope this helps if you get same bug as I did.
Edit..... thanks to king gbf who confirmed you only need to bomb the hangers