If you’re not familiar with the traditional game of Twister, it’s quite simple: you spin the spinner until it lands on a colour and one body part (left or right hand or foot). You then place that part of your body on a spot of that colour on the mat.
To pray, all you need to do is decide if you’re doing thanks prayers or please prayers then allocate a topic for each colour.
With children age 5+ I’d definitely involve children in choosing the categories. You could keep it simple like family, friends, school/work and nature/the environment. You write the topics on the mat or make a code and put it up where everyone can see it then play the game and pray as you touch each colour.
If your children are not very familiar or comfortable praying their own prayers might find it easier if they invent their prayers first then lay the game and use the prayers they created.
Of course there’s loads of different ways you can use the colours. You could thank God or pray for different types of people, e.g. Family friends, sick people and people needing help or for different types of intervention by God e.g. Wisdom, comfort, guidance, provision. Some children might like to write the name of someone to pray for on each circle. Or names of countries.
My children wanted to have all of ours names on a colour (there’s four of us which is handy!) and also the meaning of our names so we could either pray for the person (e.g. me, Victoria) or victory in difficult situations (which is what my name means).
For older children or teens, you could make a grid of topic, eg colours could be leaders, the environment, church and children, while left hand is local, right hand is regional, left foot is national, and right foot is international. This way you can pray for issues at different levels depending on which colour and body part.
If you’re really short on space eg if you do it in a pew in a service, you could do thumb and first finger on left and right hand instead of using feet.
Lastly you can get Twister from most games shops, although I’ve often found them in charity shops and sometimes on offer in supermarkets plus, I found Tiger also stock their own version for only £3.