I have been fortunate enough to spend a little bit of time with Action Henk, and so far it has been really fun. Henk and company run along Hot Wheels-like tracks and Jenga-esque towers, but the real skill comes with the butt slide, which can be used on downhill sections to pick up speed. It almost plays like Trials, in that the best times result from landing jumps smoothly.
The whole idea is commendable on its own, because it elicits feelings of being a kid, combining different toy sets to create unlikely scenarios that make perfect sense to a child's brain. Also, sometimes the floor is lava and that's awesome.