So far, I have only found tournament softball. The Singapore American Community Action Council has baseball programs for kids up through high school beginning in February, but that is as close as you will find on the island. It just so happens I work with that program, so if you can't play, would you be interesting in lending your expertise to coach?
On the softball thing, contact Andrew at clacyac@pacific.net.sg and he can fill you in on all the sordid details. They practice at the Singapore American School and have games all over the Asia Pacific region.