I had an awesome party for my twins when they were 4. We used the gym at their preschool which was helpful but the theme was camping. I set up a couple tents in the gym to play in.
We had an I Spy "treasure hunt' of sorts. I simply hid a bunch of items around the gym (not too hidden) and then made a colorful 'treasure map'. It was just pictures of the items on a sheet of paper, we passed one out to each kid and they had to run around and circle the item when they spied it. They really loved that.
We had the whole class of 16 kids so another game we played was who could put on the camping gear fastest. We had 4 lines of 4 kids, one would run down, put on an item (big hiking boots, hat, backpack etc), then run back and the next kids had to put it on, run down and add an item. Kind of like a relay. It was very comical. You could do a camping theme pin the tail on the donkey.
The biggest problem about the whole party was I had everything planned for 16 kids and alot of people brought siblings or friends and made it too big.
For gifts we did a book exchange. Every kid brings a used or new book (wrapped is ideal). You put a book in each chair or on the floor under their butts. Then you play musical chairs but no one gets out. Just do a couple rounds and then say stop. Where ever they stop is the book they get. If they aren't wrapped then kids will gravitate to certain books so it's better if they are concealed.
Although we had a gym, I bet you could pull it off at a park or in a back yard. Good luck! The twin party ideas are tough.
E. P.
Mom of boy/girl 8 year old twins who rock!