CoolN2 has been trending forever and from the reviews and personal experience, it's either a hit or miss.
Walking into the store, you have to go all the way down to the back to place your order and then proceed to the front of the store for your order. You can watch them through the glass panes as they create your ice-cream. (They also have "dragon's breath" - which is cheetos dipped into liquid nitrogen and causes smoke and can be blown through your mouth/nose to look like a "dragon" - this is a one time fun thing but def not worth another try).
The prices are a little high but still bearable. Their menu ranges from chocolate to fruits and they also have 'pop-ice'.
The process is basic: they use milk, blend it with the flavour, and then solidify it with liquid nitrogen. This process takes roughly 2-4 minutes.
That being said, if everybody decides to go after dinner ... the line is long asf. I waited half an hour for my ice-cream as my friends wanted to go. There's usually only 3 people on staff so the time-delay is real.
Overall, this place is actually not half bad but definitely not a daily thing but more of a novelty place when your friends are in town and you want to show them something cool.