Doodleman is a poor, lackluster game. If you want to play a game on a paper pad, try Border Wars.
You play as a stick figure who battles other stick figures who fall to the ground where you are. The longer you live, the greater powers the enemy stick figures will have to use against you, eventually matching you up against giant stick figures. The combat is much too simplistic, given that it's all that's happening here (just press A to attack) and since you have no reach, you'll have to attack the very moment the enemy is upon you, meaning that you end up getting hurt a lot. It plays more as a last-as-long-as-you-can game and all the while the stick figures do actually get boring to look at. There's just not too much redemeable here. Go play Border Wars if you liked the idea here because its much better executed there...