I LOOVVEEE this place! I'm so glad that they have a location in Vegas. Kona offers a great mix of American & Asian food. Not to mention the best happy-hour.
We came here twice. The first time for their main restaurant which is decent, but you HAVE to try their happy-hour. I know that it's all day happy hour on Sundays too! I normally order the BBQ Chicken pizza ($6), fried calamari, lettuce wrap w/ chicken & shrimp, and a few of the rolls. I know some of their other locations offer the Atlantic roll (salmon roll) & spicy shrimp rolls. Everything is under $8 so you can get a healthy portion of food for cheap. It's best to go in a group so that you can get a real taste of their happy-hour menu. We didn't get any drinks so I can't comment about that menu. Just make sure to sit at the bar or outside seating for happy-hour prices.
A must try: Japaleno Yellowtail Sashimi. This is a little pricier, but if you have never tried any version of this, Kona is a great place to start. They have the perfect ponzu sauce to go with the yellowtail. The jalapenos cuts all of the fishy-taste [which usually isn't present since their sushi is fresh]. I never ate sashimi before until I tried this very dish.
Enjoy!