I had 36 hours in Singapore en route to Oz over Xmas/New year.
Agreed it's not as buzzy and interesting as Bangkok or HK but still enough to do. The zoo is good, there's a cable car ride over to Sentosa Island, Raffles (for way overpiced pre mixed slings), take the lift to the top of the Marina Bay Sands hotel for the view (or even better stay there so you can use the infinity pool).
We took the open top buz around and jumped on and off at will. Might be a good option in s hort amount of time. Food we found was fine, just get off the main tourist drag.
Enjoy