Last year I made a new pixelated free typeface for my 2d game. It has Arabic, Persian, and a subset of Latin glyphs enough for English, German and Spanish texts. Inside the repo you'd find makefile to build the font and generate test outputs.
Since it was my first experience designing a typeface ever, I might have made mistakes not known to me. That's why I post this, hoping someone would point them out. Here is the repo
Yes, small e was one of the most difficult and as you mentioned needs work. Currently, it's a compromise to fit it inside a 4x4 space. I'll reiterate on it and probably post variations later.
I'll experiment with adding space inside U and V. I wanted to reuse V inside W, that's why it's so narrow.
Thanks for the feedback.
PS: and I'm really glad that you liked the lower case z! It was a breakthrough for myself when I came up with the shape on my screen. Didn't work for the capital letter though. (I also tried to avoid making it look similar to WWII SS signs)