My 7 year old son loves all superheroes, but his latest favorite is Ben 10" from cartoon network. I wasn't able to find any party ideas for this theme so we had to improvise.  For the paper goods and decorations we just stuck with a color theme of black & bright green same colors on Ben 10's omnitrix.  I made a round cake and decorated it as the omnitrix and we served green "alien-ade" which was simply lemonade with a little blue food coloring. We played four games which were a huge hit especially the first one. We made an alien obstacle course in the backyard. The kids began as the strong alien "Four Arms" and they had to throw a hover disc as far as they could. Then they tapped their own wrist (where their imaginary omnitrix was) and turned themselves into the fast alien "XLR8". They had to run through a series of cones. Then they tapped their wrist again and turned into "ghost freak" climbing up a ladder and sliding down the slide of our swingset. Next they tapped their wrist and turned into the very small alien "grey matter" getting down on the ground and crawling through a tunnel. Next they turned into the tumbling alien "wild mutt" and did a series of somersaults. The last alien was "wild vine" and the kids had to swing from a rope that I had tied to a tree. We timed all the kids and gave a prize to the top two. Even after the game was over the kids kept repeating the course. They loved it! We played "cannonbolt" dodgeball using a bright green ball.  We also played the game "E-G-G" where you throw the ball in the air and say a name. The person who you called has to get the ball while everyone else runs away from it. When you get the ball you yell "freeze" and everyone stops running. Then you take 3 steps towards the person closest to you and throw the ball at them. If you hit them they get an "E" and it's their turn to throw the ball and call out a name. If you miss them then you get the "E"...Someone is out of the game when they get E-G-G. For this party we spelled "B-E-N" instead of "E-G-G".  Last game was "pin the omnitrix onto the wildmutt". "