Two that I know of that made decent games is K-D Lab that made Perimeter and Vangers (both open sourced and recently remastered), and Nikita responsible for the Parkan series. They’re not by any means greatest hits but they’re unique and worth checking out.
EDIT: And oh, Pathologic by Ice-Pick Lodge too, but I haven’t played those. Those seem funky and definitely not for everyone.
EDIT2: There’s apparently a list of Russian made games on Wikipedia , good to know.
Lead ain’t that dangerous. Just take it out and dispose of it like you do with normal batteries. Clean your hands afterwards and you’re dandy. As for the clock, the battery contacts, and whatever they were attached to, are likely eaten away, but I can’t say that for certain from this photo. If you’re lucky and they’re mostly intact, some IPA scrubbing and a dip in vinegar, and a bit more scrubbing, should take most of the crust away. That rust though, probably some vinegar, maybe a deoxidating agent (like navy jelly?) could clean it off. Even cleaning all of it doesn’t guarantee that it’ll work any way.