EDIT: There are no more future updates (afaik) planned for the game, and IMO its a great game but wasn't fully fleshed out with all the basic features. The population has bottomed out, so if you're buying it for multiplayer then you may be out of luck in finding games. This isn't really the developers fault, as indie games have a hard time in capturing a big multiplayer player pool. It was an interesting take for a chess variant, and I hope more tactics games similar to it come out. I am always looking for that next pvp tactical game.
To Chess Players:
If you're more of a tactics player (short term captures and plans), you'll enjoy this game. Chess 2 (C2) is a much more fast-paced and unpredictable game than traditional Chess. C2 has 6 armies to choose from (there is the classic Chess army, but also new armies with unique units & movesets), and you can face any of them from your opponent, so games will have very diverse matchups each time. There are also 2 ways to win: Getting your king past midline and checkmate. This ensures games are faster and have less draws. But with the midline invasion rule, it is very "race-to-win"; there are less quiet moves, less subtle improving moves to a better position, less strategic play. Rather, its more just a string of tactical plays IMO.
Knowledge of Chess can help you in C2, but it will only help you so far. You can throw most chess rule-of-thumbs out the window, as there are new pieces with new rules. Controlling the center is good, but controlling the sides is also important as the king usually tries to flank to one side to invade midline instead of going into the center where he'll be mated. Castling early and often is actually a bad move. Fianchetto is waste of tempo, as bishops are on a better diagonal from their starting position. Knights are usually better in C2 because its usually semi-closed or closed positions. And because of that, rooks are usually worse pieces because the position is closed, but also because you castle less often providing less exits for your king rook. However, pawn majority in center is still important (if not even more important), and also the knight on the rim is still grim :-)
If you liked Chess because of same teams and starting off on even foot, you might dislike the 6 different teams. They are balanced, but are balanced in a bubble (as in they are balanced with respect to Classic Chess army, but some have advantage/disadvantage versus each other). It's a case of Perfect Imbalance (Two Kings army>Reaper>Nemesis>Two Kings). So you might dislike the fact that your army performs better/worse versus the enemy team, but it is is only slight advantage. But this provides opportunity for each game and opening to be very unique. Another factor in the game is the duel system (betting system). Whenever a piece is captured, you can bet against your opponent for the fate of the unit doing the capturing (that unit will also be removed if you lose the bet). This duel system was implemented for mind games, but it is only wild guessing IMO. It is like rock paper scissors, the player that picks his weapon by thinking 7 moves ahead is just as good as the player thinking only 4 moves ahead or 1 move ahead. Although there are limits to the betting system (you only gain betting stones by destroying an enemy pawn), and it is more complicated than I give it credit for, it is still for the most part an arbitrary system.
Overall, I would recommend C2 to chess players, because of its familiarity to Chess but also because it brings new life and something refreshing to it. The less you think of it as chess + new elements, but rather just a new board game with chess elements, the more you will enjoy the game for what it really is :) GL HF.