There's no story line here. It's a puzzle game, simple as that.
The game is awefully simplistic in UI and won't even give you any kind of clue as to what you're supposed to do. The name doesn't even make sense.
You're supposed to tag numbers for either left or right such that all tagged numbers of the same side add up to the same number as the other side.
It's really just a simple game and looks like it was a simple port from mobile or flash. As a developer I could make this whole game in half a day, on the web, and make it perform properly. I'm disappointed that they didn't even seem to bother to enhance the steam version at all.
Verdict: This is a simple concept with an even more simpler implementation. It's performance is bad, especially considering what it should do. The UI is crap and could at least help you out a little bit. The puzzles are too repetitive and, for me at least, too simple. I'm not ready to call this "a game", although it's nice and educational to some degree. This should be a website, not a steam game for sale.
Familiarity: Yeah no.