I have been working on my Terraria-ish game idea in Ebiten this past week and I can safely say that I have learned a lot - a whole lot. My proficiency with Golang has greatly increased, and I feel much more confident navigating its typing idosyncracies.
There were several programmer-induced bugs that I had to overcome - the biggest one being that the first and last few arrays withing the blockMap were empty which was because I was skipping areas for the GUI border.
I also did a lot of work on the world generation. Last time I was just placing block randomly - now I have some order. I have the world generate the dirt, sand, and gravel blocks first. Then I have a second pass over the blockMap happen which is going to place ores, etc.
Here are some example progress screenshots!