Not silly at all! My son's first birthday was Elmo themed. I only stamped the inviations, but you could stamp little treat bags for any kids--use white lunch sacks and stamp their name on it--add Elmo cut outs---(circle/ovals). My friend used the Flower from Sketch It (retired) to make Elmo----super cute! Check out the gallery for samples.
Since my son was too small to really know what was going on, I did adult games. I had Sesame Street Triva and Guess How Many Cookies in Cookies' Cookie Jar.
I did have some older kids there, so I did
Pin the Elmo nose on Kyle--took a picture of my son in an Elmo party hat and put all of his Elmos around him. I used my photo editing software to add
Happy 1st Birthday, Kyle! and had it blown up poster size at Kinko's. I cut out red noses from cardstock. I also made an
Oscar trash can by taping foil around my husband's metal sports trash can. I printed out Oscar head from the Sesame Street website and drew his hands. The kids just threw crumpled up paper (trash) in it. I also made a counting book for each child using pictures off the website.
I am a bit obsessed with my son's parties, though!
We just threw his 3rd birthday--dinosaur themed! Good luck with your party!