Have you tried Video Walkie Talkies ?
The children love playing Avengers, and they are always asking me am I Team Cap or Team Iron Man, it now makes sense after watching Civil War!
The only trouble they have is communicating when they are charging round the house or the garden, I have enough trouble yelling them fro the bottom of the stairs, so if they are trying to whisper, there is no hope (unless of course they are all just ignoring me!)
Each of the handsets required 3 AAA batteries, the instructions were very easy to follow and within a vfew minutes we were up and running.
All of the children adored them for different reasons, Kaide thought it was hilarious to place one in a room and start making ghost noises whenever one of the other children came in, Tyrus and Viggo were mesmerised that they could see their brothers and sisters on the screen even though they were not in the same room.
Neva and Xene were extremely impressed with them u the other end of the garden as they could communicate easily. The range on them is approx 160 ft, so plenty of room to move away from each other, they quite frequently have one of them upstairs giving orders to the ones downstairs!
Each walkie talkie has a little square at the top so you can position yourself and make sure the other person can see you, which the youngest two thought was great because they could see themselves and whoever they were talking to.
The walkie talkies can be purchased on Amazon for less than £60, they are well made and the video element certainly held the children’s attention, we would definitely recommend them.