Walls

Here's what that previous scene looks like with walls (and a gun sprite) added in:



Almost like a 15 year old FPS! :)

Like I said, walls are pretty easy to make. A Doom level is basically a top down line-drawing, where each line is a wall. So to generate the walls you just create squares from floor to ceiling at each line. If the line divides two rooms then you punch a hole in it (like the little window in the video).

PS: Apparently Gloom is already a game, and it's a Doom clone as well. So I need a new name. Maybe "Mood"?