What are the important factors I need to consider for a good preschool in Singapore? Please let me know what influenced your decision-making

What is my view on a good preschool and I list them down and research on the preschools based on my view of what is a good preschool. Every preschool has their own advantages and it's not critical in my consideration. More importantly is my criteria to search for a preschool, which is distance, environment hygiene and safety.