Is this actually a 3d game? Or did you use raycasting? It's very cool! I'd love to know more about the tech behind it. What suggests 3d to me is the way the outlines of the cones change in black-and-white mode.
It's all 2D, calculating their x, y and scale based on their distance from the player. I draw the cones using two triangles, and in the black and white version I added extra outline-only triangles. Getting the collisions feeling correct took longer than anything else in the game!
