DS will be 6 this year and wants a Lego Ninjago party. His idea basically consists of inviting his friends round to watch Lego Ninjago on the telly and maybe eat some cake. This would be fine apart from that fact that none of his friends like Ninjago. DS doesn't seem to think this will be a problem and doesn't seem to mind the fact that we will just have a houseful of slightly bored children who i'm trying to entertain while he's watching telly!
Last year we had a party at a local farm which was really successful but partly because we were very lucky with the weather. I'm basically trying to think of something not too expensive where about 8 or 10 children well be entertained for a couple of hours. Children will be aged from around 3 to 8, mainly 6 year olds. DS doesn't want soft play or swimming.
Preferably ninja related.