As is customary in many korean restaurants, if you want service you're expected to push a button on your table - otherwise, servers will leave you alone.
That being said, the food here was simply "okay" at best, even during normal dinner hours. With so many other Korean places in the area, you can probably do better.
I was also a bit disappointed - we had a group of 8 and asked if cheques could be separated and they said they couldn't do more than three cheques for our whole group. I get that it's tough to draw separate cheques but if we ask in advance, doesn't that make it better?