1. Andaman has very limited option for adventure, only one or two good scuba dive companies and very limited things to see when scuba diving. 2. Singapore has loads and loads of adventure activities to do, but not so much closer to nature(options are less).
3. Bali is quite unique in terms of nature and as well as adventure. If you plan well, chances are there to visit LIVE volcano and bake potato in live volcano and have early morning breakfast!!!.