There is a 24 hour welcome in mongkok too. I have been there buying bananas at 3 am. ..
I've seen people get on the Monkey Mountain minibus at 5am with boxes of bananas. I don't recommend that for your stopover though.
Here's what we ended up doing:
Causeway for dinner and walked around.
Made it to Central for the last ferry to TST
Walked around tst.
Stumbled upon a game arcade, which was a unique experience. Played some racing games, and Jubeat, a japanese rhythm game.
Went to Temple St. around 1:00am, and to my surprise many people were out eating at the dai pai dongs. Had chinese desserts there.
Went to Yau Ma tei fruit market, and had Kiwiberries for the first time.
Sat at two mcdonald's in Mong Kok to rest.
Caught the first train to Central and went to Victoria Peak.
yeah, a quid a game, worse of all, service stations, crazy, 2 quid a game ( for sub ps3 , closer to ps2 quality ) for an arcade ! at least the equivalent to max HK$5 per game, though I believe some Namco wonderpark wasn't cheap or was jumping gym probably cost more than HK$5 as it was tokens
but the arcade industry is dying throughout the world
there are 24 hour snooker billiard places
and quite a few takeaway/café places open 24 hours