The phrase "straight path" means taking the most direct route or following a direct and honest approach instead of taking a longer or more complicated route. Full definition
XIII consisted largely of straight paths leading from one battle to another, with no room to explore or return to anywhere interesting, and no towns or cities to roam, either. (plusxp.com)
The game suffers from the «use the tape on the cat» syndrome: twisted logic actions and denied straight paths. (metacritic.com)
What they found was that the dung beetles rolled in straight paths and made it to the periphery quickly using natural light from the moon or a moonless starry sky. (sciencemag.org)