You could do a trivia game, where there are questions either about weddings in general, or questions about the bride and groom (or both)! Or you could do a photo scavenger hunt, where everyone is given a list of things/scenarios/people to take a photo of throughout the reception (someone dancing, something blue, a photo with the bride and groom, a pair of sunglasses on an inanimate object, etc).
We did the newlywed game and we did a toilet paper wedding dress contest. We also did a contest for couples that were married by so many years. So we honored couples who are married the longest to the newest. It help pass the time while we were taking pictures.
We did 2 wedding party games that our guests loved. 1. The bridesmaids went out into the crowd for a scavenger hunt that was like musical chairs, every time they came back with an item there was one less chair. 2. The groomsmen did a blindfolded dance off that was rigged for one of the groomsmen to dance alone. It was hilarious.