In the last couple of days I've been working to improve the lighting engine. I've added support for multiple lights as well as a small trick that renders shadows onto vertical surfaces. All the lighting calculations are now based on the game's internal resolution (the sprites resolution). The processed frame is then rendered with a transformation matrix that scales it up. This behaviour allows me to get that pixelated low-res look I am after, and should also speed up the lighting engine calculations. It's also a way to achieve resolution independence. I've also upgraded the player sprite with a (flat for now) normalmap and a heightmap, so it's showing correctly now. One thing that bothers me is the artifact that shows during the walking animation, which wasn't present before I started programming the lighting engine and was probably introduced somewhere along the way.