L.R.
I hope this doesn't sound too obvious but...Google "kids games indoor" and see what you get. I have done this for our scout meetings and found very good, original games I'd never have thought of, games that are different from the usual list of musical chairs etc. You could even add an age range to the Google search. I've found international games from other countries, too.
A game our kids all like is a simple balloon race -- blow up balloons (not helium!) and have the kids form teams and race while hopping with the balloons between their knees - if you drop your balloon you have to return to the start and do your part of the race over again. There are other variations like partners keeping the balloons in the air the longest, or passing the balloon from under the chin -- kids can only hold the balloon against their chests with their chins, and have to try to take the balloon that way from the previous person in a line and pass it to the next the same way.