Just seen this in CycleClips. It seems to be official policy that it's children's fault if motorists run them over...
Whether its kids or adults, it common sense to be as visible as possible whilst out on the bike, especially at this time of year.
I have just seen your 'game' on the following website:
http://talesoftheroad.direct.gov.uk/be-bright.php
This game could easily lead children to believe that wearing high visibility clothing makes them safe on the road without the need to look out for oncoming traffic. It also implies that if a child is not wearing high visibility clothing, then it is their fault if they get hurt, rather than the fault of an inattentive driver. Surely safe behaviour around roads is more important - even the most careful driver cannot avoid a 'high visibility' child if they suddenly run out into the road.