Shadows Casted, Lessons Learned

So! I've uploaded my first thing here. It's unfinished and basically just a demo, but still, it's a thing where you can move around and things happen on the screen. Specifically, shadows are cast.

My current implementation is not the most efficient one, but it does its job. It also took a while to get right. Here's a look at the special mode I created for debugging lighting issues:

(The edge colors indicate what side of each tile was tested, and the numbers indicate how many obstacles my logic things are between the player and the tile in question. As can be seen in this GIF, at that stage it was sometimes possible to look through walls.)

All in all, an interesting experiment and lots of lessons learned.