Use the arrow keys to move, space to turn torch on and off (If you run out of torch power you can't use it any more), and most importantly don't run into any bad guys.
Music from Paper Mario Colour Splash made by Nintendo. Tips for beginners... - Don't keep your torch on for long periods of time, as you may eventually run out of power - Don't shine your torch on the bad guys, it will give away your location - Whenever a flash of lightning happens another bad guy will join the game