Ooooh, how I don't look forward to shower games. I liked one: Every guest wrote down 5 things that they supposedly had done but only one was true. THey all seemed rather surprising and out of character. The honoree had to guess which one was the true one. If the Honoree guessed wrong, they got a little prize.
We got many laughs out of that one and it helped with conversation starters when we mingled later. Course, two people said things that, well, even the one that was true was probably something that they shouldn't have told about themselves. One of them my daughter was embarrassed to guess anyone of them could be true. You don't have much control out of what comes out of their mouths!
Consider something that helps people get to know each other. Prizes for the people that travelled the furtherest, non-family that knows the honoree the longest, has the most children, who has the longest name, etc.
The ones I like the best are the ones that have good tasting hot and cold appetizers with a pitcher of good, fruity martinis or white wine or a good punch. Cake is eaten while the honoree opens presents.
Hints on presents. Many treat it as found loot. They don't call out the persons name, look up, acknowledge them, say thanks. They might say "ooooh" or "wow" and then softly say the giver's name to the friend recording them. That's it. Our family goes even further by getting up to go hug the gift giver. Also, start with the smallest presents and work up to the biggest presents.