Giving it 2 stars for the music (on the ground floor only)...crowd is just about OK, food is too bad, cocktails suck, dance music on second and third floor is repetitive and becomes boring after 30 mins or so, waiter kept pestering us to buy more drinks and is over priced.
Is overhyped...so maybe you can try it once just to say "Yeah I've been to Hawaiin Shack"...LOL
If you do go, stick to drinking and dancing only, don't experiment with food. Dancing starts around 10.30-11.00'ish on the second/third floor and goes on till closing time.
Hope you enjoy more than us :)