No, you are not crazy. Do you have a park nearby that you can rent a pavilion or put up a tent?? Outdoors seems like a great idea this time of year--especially for boys. You can do some simple games (ring toss, egg on a spoon, water balloons (if the weather is really warm), pin the tail on the donkey, etc)...just google, you can come up with hundreds of ideas!
A friend did an awesome theme last year. Her son is a huge animal lover. They did a dog theme (and they don't even have a dog). They did pin the tail on the dog, dog toy toss, and they had to transfer water from one dog bowl to another. The best part---in lieu of gifts, they asked people to bring pet food to donate to a local shelter. LOVED THE IDEA!!!! The cake was in the shape of a dog bone, too.
We ALWAYS ask for donations(paper towels, trash bags, toilet paper, etc) to the Ronald McDonald in lieu of gifts for the kids. It's a win-win-win....parents don't have to stress about what to buy, you don't end up with 20 new toys your kids *might* play with, the charity of your choice benefits!!
Also, I never feel the need to buy/make goodie bags because my kids aren't receiving gifts. Parents ALWAYS thank me! They'd much rather buy 5 rolls of paper towels for less that $10 than worry about what my son needs/wants and how much is appropriate to spend!