"[A] really easy game to play with all ages is Simon Says. The aim of the game is to catch the kids out but we play it as a way to keep them occupied if we are delayed somewhere or to burn up energy on a rainy day or as a party game!
The way to play it is as follows: One person (usually the adult) is the caller. The caller shouts instructions, e.g. 'Simon says, dance Gagnam style,' 'Simon says, hop on one leg 50 times.' If the caller says 'Simon says' then all players have to obey. If they do not say 'Simon Says,' the player should NOT do anything! It's a really fast game and the kids get so excited that they concentrate on the instruction and forget about the 'Simon says' element. It's great fun catching them out!
Here's some examples of instructions. If the kids are older it's great to keep changing the instructions quickly. If they are younger, go a bit more gently! Simon says . . .
You get the idea! You can make it as physical as you like in short bursts which means it'll burn energy but not get out of hand! Enjoy" — Niamh of Daisy and Finns Party Ideas