FYI, I recently posted about a 2d game I made, here: https://news.ycombinator.com/item?id=41761517

Putting aside the politics and all, focusing on the tech- one thing I came across when trying to do my own collision detection was the idea of using the GPU and occlusion queries for pixel-perfect results.

I didn't come up with the technique, but it's super cool, and since you're not taxing the GPU with tons of 3d triangles, it's perhaps a bit more free to do stuff like that.