Head down to the library and borrow books on exposure, in low light conditions, flash is useful and useless, based on what you've said you've shot,most likely in scene,flash would be useless
Think about this, you go down to hardware shops and buy a normal flashlight, if I were to have you where you were when you shoot, and all the lights in Singapore were turned off, and you shine your light at something far away, it won't be lit up,simply because the flash isn't powerful enough
Also, the shutter speed wasn't open long enough, consider this situation, if I blind fold you, and I ask you to describe to me what you see when I remove the blindfold, I just open and close almost immediately, there isn't enough time for your eyes to capture everything,similarly in night landscape, because there isn't enough light,it takes time for the camera to "see" everything in detail
Honestly,my explanation isn't the best,I highly recommend you go to the library and borrow some books to read up on basic exposure
Film or digital,all methods are the same, even different formats,compact cameras,DSLRs and whatever other types there are,all are based on the same principles