We've done the baby food game too but we didn't open the jars.
There's always the clothespin games. Give each person a set number of clothes pins and see who can drop the most in a bottle. Or each person stands up, reaches between her legs and pins the clothespin as high up on her back as she can reach. It's really funny to watch.
Something fun and different for the mommy to be... Make a scrap book using baby pictures from magazines. Leave room on each page for the mommy to fill in later with pictures from her shower and a place to make a note of each gift and who it was from. On each page of the book give her a clue as to where her gift is hidden. Simple things like, rub a dub dub, look in the tub or don't despair, look under your chair, don't be a slouch, your next gift is under the couch. As mom is finding her gifts the host can fill in the scrap book or make a list for mom to fill in the book later. I hope I described this well enough for you to get the idea.