Anyone else struggling to get the goal for killing nothing other than the boss for any level to unlock? I've tried several times now with level 1 and it's not working.

Don't think I've ever seen that to-do list item, but there are a couple others that either don't work, or auto-complete without even needing to do them. I wouldn't sweat it -- there's always other items to complete for upgrade money, even though you might have to wait till the next in-game day to get them. :)

No this isn't an item on the to-do list, it's a goal for the arcade game. I'm going for a completionist playthrough, hence why this is bothering me

Oh, well, that stinks. Doesn't surprise me that some of the machine goals are also buggy, though. Maybe the devs will patch it at some point -- the game's not too old, and it's not even been quite a year and a half since the last update here. Honestly, though, I'd consider poking the devs on a service where they're more likely to see your comment -- Steam, their Discord (if they have one), even just regular social media (or good ol' e-mail). I don't know how likely they are to see your complaint here. ;)