I wouldn't say that having games at a baby shower is in itself bad, but I definitely do not like the diaper one.
It is gross and I don't see the fun in it at all.
I think doing something creative is great, we did this, I've also seen people do coloring pages of the alphabet for an ABCs book for example. You can extrapolate the same game out and decorate blocks as well!
And, instead of paint you can do iron-on transfers by getting some heat-n-bond (at a fabric store) and ironing it on to cute fabric, then cut the shape you want from the fabric, peel the backing, and iron it on the clothes!
Also, throw in some toddler sized t-shirts to your decorating pile. I hear new parents get tons of clothes for baby that they'll grow out of super fast, but the kiddo will spend more time in toddler clothes.
Another hilarious idea I saw was to take screenshots from horror movies and from women giving birth (or just still pics) and crop it to just the lady's face. Then you play "Labor or Horror Movie?" and have people try to guess which movie it comes from.
Don't do this if the mom to be is scared of labor, though.