Chess is a pretty good game, I hear, but I'm not really into retro gaming. After literally centuries (not to mention countless mods and patches) someone has finally made a proper sequel, so I might give it a crack. While the original Chess only had one faction, Chess 2: The Sequel adds another five armies with different rules, along with duels and a new victory condition.
It's still kind of retro though, not upgrading the graphics at all. The story's pretty much that same old war tale, though now it does now include ghosts, tigers, and elephants. A bit Far Cry 3-ish, then.
Each army changes how a few pieces work or gives them new rules and names entirely, such as teleporting Queens, Knights who can capture their own pieces, Elephants that rampage when they capture pieces, and units which boost others nearby. That new win condition is intended to speed up the endgame and stop stalemates, by letting players win by getting their King across the half-way line. And the final new thing is duelling, where players having a piece captured can try to take the attacker down too through a duel of blind-bidding 'stones,' a limited resource.
If you want the full rundown, you can download the rules for free. They work with any old physical chess set if you have one. Chess 2 has a few fans amongst serious tabletop folk, whose word I'll certainly trust over your average video game reviewer in this matter.
Given that Chess is 500 years old (or 900, 1,500, 1,700 years, if we go by the Early Access, alpha, or pre-alpha release), frankly I'd hope for more drastic changes in the sequel, but there you go. It's hardly Resident Evil 4, is it?
Chess 2's rules were designed by David Sirlin (famed for rebalancing Super Street Fighter II Turbo HD Remix, I'm told), but the video game's made by Ludeme Games. They first released it as an Ouya timed exclusive to score some of the money the Android microconsole was tossing about, but now they're bringing it to PC in "the very near future."