When developing video games, gameplay metrics allow to track and analyze the behaviors of users interacting with the game. Here, we propose to harness player's spatial trajectories to objectively quantify their gaming experience. Spatial trajectories are complex signals that are determined both by the players and by the topology of the virtual spaces they evolve in. In this paper, we propose a new methodology to measure and visualize how the entropy of trajectories is distributed in virtual spaces, and explain how it can inform game developers on the design of the game levels. We apply our method on the Sea Hero Quest dataset, consisting of the trajectories of over 4 millions players finding their way in water mazes.