I played a Palazzo slot tournament in early April. The icons that you have to touch are worth more points than the spins. And the last 30 seconds is at 5X making the first 2:00 nearly worthless. It went 1:30 at 1X, :30 at 2X, :30 at 3X, :30 at 5X. I saw an old guy not paying much attention to the icons and he was the lowest score of the 50 in his session.
There is about 95% luck and 5% dexterity skill involved. Some people could definitely get tired and miss some spins. Most people are playing at the spin cap - you can press spin 3 times a second but you'll still only get 1 spin every 4 seconds because it's capped.
Locally they use the TournEvent machines. In those you have to pop balloons but there's only 5-10 that show up in the 3 minutes compared to the probably 30-50 icons in the one above.