I arrived about 30 minutes early and waited, but since others had written in reviews that they wouldn't let you in until the last minute, I took pictures and killed time around the area. However, when I went back 10 minutes before the start, I was able to get in smoothly without waiting! It didn't seem like they were particularly strict about the timing. I think it's convenient to print out your ticket and keep it handy, but mobile tickets on your phone are also perfectly fine!