I have two boys 4 & 6. Both love pinball (especially the 4yo) and in our small collection they love Spider-Man and the Hobbit most. They think mousin around is too fast and counterforce is too slow.
I recommend showing them lots of videos of gameplay to see what they gravitate towards. Or better yet, take your kids to the silverball museum in Asbury park or modern pinball in nyc to play a bunch of different games to see what they like playing most.