MineFlat (Terraria Port)

I few months ago, I decided I’d try my hand at LWJGL. I started with a 3D game, and quickly found that I was in far over my head. Shortly after my failed attempt at a game, I decided to create a port of Terraria called MineFlat. It’s not even close to a playable game yet, but I’d just like to get a bit of feedback on what I’ve done so far. I’ve created a terrain generator, a basic player physics system, and a lighting system (most of these systems are completely broken on the negative side of the x-axis; this is the reason for the wooden wall at x=1). Like I said, it’s not much, but I’d just like to know what I should improve.
Link to the launcher is here, link to the game’s Jenkins task is here, and link to the game’s source is here.