Also, I was checking if there are any threads about things to do or must-visit attractions in Singapore but couldn't find any. Thus, here are my suggestions in case someone will be searching for it in the future. Hoping I could be of help.
With the limited time I had during the trip, I was only able to visit these:
- Changi Airport
- Orchard Library -
- Gardens By The Bay
- Fort Canning Tunnel
- Marina Bay Sands
- Chijmes
- Haji Lane
- China Town
- Little India
- Merlion Park
- USS
Singapore has so much to offer but if you have limited time, you may consider a private tour https://gowithguide.com/singapore to customize your trip and never miss the city highlights of Singapore. Though, mostly local suggested to spend 2 weeks in the country to enjoy and visit all the attractions.