For something exhilarating but not on the snow try the Luge ride in Megève – at any time of the year.
Just beyond the sports centre in Megeve, in the Balltrap (ouch) area at the bottom of the Jaillet ski lift, is the Luge ride. Top up a Megève lift card with ride tokens and get in the queue for a car. Get hauled to the top of the hill then take off! Speed is in your control, push forward on the handle to go faster.
The more tokens you buy the cheaper it is. Also, each token is for one car, so two sharing will make your money go further. And sharing the experience is even more fun. Little ones can ride with an adult.
There’s another one – possibly even bigger – in Les Saisies: see here