Draw Race 2
"Draw Race 2" is simple - as you can see here: http://www.youtube.com/watch?v=TpWSzuClc1o&feature=player_embedded .
Just "draw" your way to drive and then have fun :-)
It has got an career-mode with 180 challenges and it has got an offline multiplayer-mode, so you can share your experience with your friends. For more information see: http://www.redlynx.com/games/drawrace2 .
Briefly said: It´s a perfect game for a smartphone!