Money Idol Exchanger is one of those weirdly addictive puzzle games that snuck onto the Game Boy after starting in Japanese arcades. At first glance, it looks like your standard match-three thing—swap coins and bills to make combos—but there’s this whole layer of currency conversion chaos going on. Yen turn into dollars, then into pounds, and suddenly you’re sweating over exchange rates while the timer ticks down.

The Japanese version has this bizarre idol theme with a peppy announcer cheering you on, which got stripped out in the Western release (of course). It’s fast, a little frantic, and way deeper than it seems—I lost way too many bus rides to this thing back in the day. If you like your puzzle games with a side of economic panic, this one’s a hidden gem.