What are some fun and unique 50th Birthday party ideas for mother?

I need some fun and unique ideas for my mom's 50th suprise party this summer. It's going to be inside and outside, but mostly outside. I need some good games. I am worried that it wont be fun, and it needs to be absolutly perfect! I am on a budget, so any ideas on things I could make would be awesome. I want to be creative.. I am just so nervous that I cant think of anything that stands out to me. She's not the type of person who's old, shes a very fun person and loves pretty things. So no over the hill ideas. I need to set a good vibe.