You seem to have had the same idea as the developer of They Hide in the Shadows, and it's done OK, it's just lacking in feedback and such.
Thank you for your comment :D I didn't have the chance to try They Hide in the Shadows because I've been busy and only tried browser playable games! I just checked out the screenshots and it seems a 3D and more complete version of the same idea!
I hope they do good :D
