I bought my ticket on Ctrip and arrived half an hour early. I still had to queue and exchange it for a paper ticket. Entry was based on the time indicated on the ticket. The ticket has a QR code, which you scan after each round. A round of ziplining takes about three to five minutes, but the queues, including for the zipline and the cable car, can take about half an hour. We went during the summer weekend, so it was incredibly crowded.
Before you go, choose a helmet that fits you and wear it throughout your rounds. You can buy tickets on the spot, but there are no single-round tickets; the minimum order is two rounds. After each round, you pass a screen area on your way to the next round. Scan the QR code on your helmet. Your zipline video and photos will appear on the screen. You can purchase them, but they refresh with each round, so it's recommended to review your photos and videos after each round. There are four lines in total. The first and last sections are the same track. There's a split in the middle, where you choose your favorite color track and then merge again at a certain point. Don't worry about not being able to slide! The controls are simple: pull back to brake, and slightly push forward to advance. Everyone starts at the same starting point for the first round. Staff will be there to guide you, and you won't be allowed to start until you've mastered the technique. If you're taking the MRT, follow the signs up the stairs after getting off the station. The starting point is at a higher point. Slide down, then take the cable car up, slide down again, and then go back up again. There are two cable cars, and there's a fork in the queue. You can choose which one to take. The right one is higher and offers views of the Sentosa beach, while the left one is flatter and less scenic, making it suitable for those afraid of heights. However, the panoramic view of Sentosa can only be seen from the cable car.
We visited Universal Studios during the day and bought tickets for the 4 PM luge ride. We felt a bit pressed for time, so we left before finishing the ride. We were worried about being late for the ride and getting dark, but Singapore gets dark late; it's still light at 7 PM. The three rides took about two hours, and we spent quite a bit of time looking at our own videos and photos. Overall, it's worth it. I recommend buying four rides. Since you're here, you should experience it.