Nice, good job!
1. Damn that's what I get for rushing and not spell checking, oops
2. Ah yeah so that's because the font only scales properly at 16 and 32 font size (or larger sizes like 64 too but that's way too big for a game that's 540 pixels tall lol). But that text is 24, so there's some non-integer scaling happening, so some of the pixels get scaled to be. I think I actually did notice it ages ago, but forgot lol. I'll up it to 32 so it's fixed.
And yeah I agree with the difficulty changes.
I'll release a 1.6.1 update with those, and possibly other fixes/changes in the next few days
Edit: The patch is out now