Thanks for your feedback! I don't know if I get you wrong, but the batteries do respawn. There are multiple spawn locations in the maze where one of the three items can spawn (in fact, the items spawn randomly at these locations, but they have some spawn chance. Batteries have the highest chance to spawn, though).
A riddle would be cool, I agree. I also though abot some items that indicate a path or something, but that would have taken way too much time, because that would need an implementation of a pathfinding algorithm, which I am not familiar with yet. But if I ever plan to create a remake / extension of the game, this is a cool idea to consider! Thank you. :)