Glad you enjoyed the game, thanks for playing!
That's motivating to hear that you think it has commercial potential because I've been considering it. Faith is another 2D top-down horror game that has three games and I believe has done well for itself. So there's definitely an audience. I'll be figuring out how to take advantage of my angle and surface with Dead Rubicon and see where I can take it.
Getting that mouse to work properly has been a real piece of work. And with multiple monitors, I find that the mouse cursor doesn't constrain to the game window, I need to look into that. I heard it may be a WebGL issue. Your suggestion of constraining it horizontally so that it rotates by moving left or right is a nice compromise I'll look into. Having a cursor as well is a good idea, and someone else has recommended it too!
Regarding the art and colliders, I'll be putting in the work to better distinguish them for better traversal. Also looking forward to sprucing up the art some more.