Mostly finished: Latin, Cyrillic, Greek, Kana.

X-height tends to be about 5px, with maximum 2px descenders and 2px ascenders. Cap height is 7px. Width generally 4px for lowercase and 5px for uppercase but depends on the letter, spacing usually 1px. Han characters aren't very doable at this resolution. including them is mostly for fun.

Update: Removed hangul and han characters to avoid mismatched writing (there would still be pixel kana alongside nonpixel han characters but hopefully that wouldn't be as jarring as having only some han characters be pixelated)