I purchased discounted tickets for this attraction. The full price is a bit much but stop by a Tix4Tonight kiosk. I paid about $28 for admittance and the use of the handheld device to avoid draining my phone.
Every worker there was so kind and helpful -- the best customer service I've received in Las Vegas so far, even after having visited high-end businesses. They deserve a raise!
The shop has a nice assortment of items. Most items are things you'd be able to buy elsewhere at a cheaper price, but they do have some exclusive items like T-shirts and keychains.
As for the attraction itself, I had fun. I went first thing one morning and the group I was with was small enough to where we didn't get in one another's way. There's plenty to read and see. I used the handheld device to play along and my phone to take photos. I'm new to the Marvel fandom and could answer most of the questions without clues.
The way the attraction is set up, you enter an area dedicated to a specific Avenger. You answer questions related to that character and can see their props and costumes.
The Iron Man area was my favorite with its various suits and a Hulkbuster.
While the game was fun, the best part of the experience for me was seeing the film costumes. I went through the attraction much slower than most so I could take my time enjoying everything. It took me around a hour.