SIN Airport

I've always wanted to visit the Sinagapore airport and I'm tying it in with a visit into the city next month. I will be arriving just after midnight. Is there any way to stay in the transit area after you arrive? I will be staying in a hotel the following night but it will be too early to check in when I arrive. All the fun things I've wanted to check out are in the transit and departure areas, not arrivals. I would love to spend my time exploring the airport that night/morning before checking into the hotel and then just when departing the next afternoon. I don't want to do anything that will get me in trouble with customs or anything. I know they have city tours that depart from the airport that you can register for in the transit area.

Our trip in Sept was on Garuda to SIN with continuation flight on DL. We were permitted to stay in the transit area simply since we chose that option. Didn't know if it would work and it worked perfectly. We had 8 hours, so we checked into the Priority Pass Lounge with our membership. We had to go the transit desk (opened 3 hours prior to our flight) and get the agent to activate our listing and check us in. It was a great experience! PS--we did have to check our bags in Denpasar. Normally we do carry-on only.