Sentosa day: USS or Oceanarium
Thrills and characters: USS at weekday opening. AC, ocean stories, fewer coasters: Singapore Oceanarium. Adventure Cove adds heat and wet. Decision line: do not run Oceanarium / USS / wax museum as three tickets one day.
Mandai day: Zoo + indoor play or rainforest
Toddlers / rain: Zoo half-day + Curiosity Cove slot. Willing walkers, older kids: Rainforest Wild Asia for half a day+. Night Safari needs its own evening. Never USS morning then Zoo afternoon.
Common mistakes and who it suits
Common mistake: “it’s all Singapore so it fits.” Who needs two family days: toddlers or ticketed parks. Who can skip: adult food-and-walk trips — Chinatown / Bay is enough.