Indoor Party Games

Use a nerf gun to knock down stacked solo cups , or a water gun if you can do it without it being a total mess

hot potato

twister

freeze dance

throw ping pong balls into buckets

oddly they still LOVE duck duck goose even in first grade ive learned

get a baby pool and have them either dig in sand for treasure or fill with water and tie magnets on sticks and have them go fishing

sports things like jump rope, or ladder ball, or small obstacle course

throw a football through a board with a hole cut out

make a sports car station with crafts

You could do spoon races...it's still a race but not a ton of running! You can use real eggs or even just hollow plastic eggs. I would also do a craft of some kind at one station. You can buy great pre-packed (read organized) from Oriental Trading Co for cheap. Michael's has some too but they will be pricier. You could also maybe do a cupcake or cookie decorating station and that could be their party favor. Something else fun is for them to make their own "trail mix" and put it in a baggie (also part of the party favor). You can use dried cereals, fruits, small candies, nuts, dried fruits, pretzels, marshmallows, etc.

Other games might be simon says, freeze dance, musical chairs, pin the tail on the donkey (or other themed thing to pin something to), bean bag toss, duck pond, lollipop tree, ring toss...

Limbo is another favorite.

Family fun always has some good games. Look on their site. Bean bag toss is always fun. See if someone can cut three holes in some plywood for you.
I bet pintrest has some good ideas!

Red light green light

send them on a scavenger hunt

I can't remember the name, but the game where you divide a space into two sides, then give them each a bunch of balls or something and the kids try to get all the balls onto the other teams side before time runs out. Something about messy backyard. Team with the most stuff left on their side at the buzzer is the loser and team with "cleanest" backyard is winner. Did this at a 4 year old party recently and it was a lot of fun

Carnival style games....bean bag, ring toss, etc. You can get those from Oriental Trading Company sometimes on sale :)

Google Minute to Win It games for kids. We've done many of these. Supplies are easy and cheap. You can write out directions on an index card, or play them with your son and he'll most likely remember how you play. This works for kids of all ages!