Solipskier is a port of a popular (and free) web game where you draw a path for a speedy little skier through a course full of gates, walls, and tunnels. Your finger essentially creates the jumps, slopes, and plateaus; wherever you hold your finger, you generate a surface. You need to guide your skier through the gates and tunnels by watching markers on the right side of the screen, which indicate the altitude of and the distance to the next goal. The more gates you stack up, the higher your bonus. And the longer you go, the faster your skier.
This is one of those single-track games that works exceptionally well on an iDevice, kind of like Canabalt or Monster Dash. You have one singular goal, but speed turns it into something of a juggling act. Can you keep performing as things approach a boil? That's what keeps Solipskier addictive and something you return to time and time again when you have a few moments to spare.
I also really like Solipskier's art direction. The scene is various shades of gray, but when you get going quickly and nail gates, a rainbow-colored scarf flutters in the wind behind your skier. It's a great indicator that you're doing well. Solipskier also has an excellent soundtrack, which includes riffs on classic music.
Solipskier is a universal app, too, so it runs native on both the iPhone and iPad.