Can A 15 and 16 year old teenager go without an adult?

Yes.

100% they can. I highly recommend purchasing the full day package. Two hours isn't enough and the time flies, especially on the weekend

Absolutely. It's like playing video games at an arcade, but with a much quieter atmosphere. The staff is very helpful and assist you at every VR rig. They should have a fantastic time.

Yes, the staff is very helpful and gives you 200% of the needed attention and instructions. They are at each exhibit, and will train you on how to use the exhibit before you start.