Chalk

The premise of Chalk is brilliant but simple. On a chalkboard come to life, you must guide the heroes Line and Target through six intense stages filled with monsters and environmental challenges, facing off against mini bosses to earn checkpoints and fighting incredibly imaginative end level bosses in each stage. You do all of this by left-clicking and holding while moving the mouse to draw lines through points on objects, between enemy shots and the enemies themselves to reflect the shots back, and various other actions which I won't spoil, as it's fun figuring this sort of thing out on your own. It's a beautiful but largely monochromatic game, keeping in theme with the setting, and all the artwork has a suitably hand drawn feel to it. The music is simple but upbeat, and the controls are perfect. I would pay money for this game on WiiWare. It's free for download on the website, and I can't think of a better way to idly spend 30 minutes than with this game.