Ski Safari does not really feature a safari, at least not if I'm understanding the word correctly, but it is a pretty fun game that will manage to keep you occupied for ten or so minutes at a time... Or more, if you're really, really good at it.
Ski Safari is an incredibly simple game. You ride down a 2-D mountain (it's a side-scroller) on skis while an avalanche chases you. Also, you can jump and do flips. Oh, and along the way down the mountain, which may or may not go on forever (the avalanche always caught me), you will encounter penguins and yetis that you can ride on, and if you ride through a cabin, you might just come out the other side on a snowmobile.
It's good to ride on things, because they make you go faster, and if you don't go faster, the avalanche hits you.
The objective, as with most phone games, is to get a high score. The longer you go, the higher your score will be, but you also get bonuses for doing flips and collecting coins and riding on things. So you'll want to do that stuff.
There is joy to be found in this game, and its simplicity is a virtue. It's the kind of mindless game that can keep you occupied for any stretch of time, but it's so slight that you may forget it's on your phone. But you'll enjoy yourself when you do remember to pick it up and give it another go.