Some of their puzzles have multiple solutions and they only accept one as "correct".

This is not quite as well-built as Zen Chess: Mate in One, but it's OK for an afternoon if you're into chess.

Some puzzles have some serious set-up issues. 90, for example, has multiple pieces in single square and has two solutions, but only accepts one. Ever puzzle after 90 has a white rook on f8 for some reason and you cannot interact with it.

Game still allows illegal moves and does not show why your moves are incorrect.

Music is still really loud and has no way to control in-game.

Can't recommend the game as a chess tool. But if you know a bit about the game and feel like getting a few quick achievements, it's decent.

Not a true "mate in two" game, I wouldn't recommend this to chess lovers. The opponent makes illogical moves on some levels that make zero sense, but there is no other way to beat the level, so you have to roll with it. There are also multiple solutions on some levels, but the game only ever accepts one specific set of moves. So you end up clicking around like an idiot trying to figure out which one it is.

Another problem with the game is that if you make the "wrong" move, the board just resets. It's just not very intuitive to your average chess lover, IMO. For 60 cents it's probably worth the cost, but the dev didn't seem to know how to properly build a "mate in two" game. Maybe "mate in one" is better, since it wouldn't allow for these stupid scenarios from popping up

+ Fast and responsive
+ Multiple design elements
+ 150 chess tasks to solve

Your turn is taken back if You try to go another way than game makers thought. First Fire to the King is mostly the correct way.

It's exactly what it says. A very pleasant and calming chess tactics game. There are some minor customization options with the pieces and colors. My only gripe is usually with tactics puzzles we get to see the move prior from the opponent, which this does not do, but it certainly isn't a gamebreaker and maybe even helps with the minimalistic idea more. If you know how to play chess and/or like chess then this is a nice little relaxing way to do tactics from your computer.

Puzzle 6 has two solutions but the game only accepts one.

nice game for chess enthusiasts!

It's okay. I feel it is oddly constructed, however, as you can simply try various moves until it accepts it, making guessing the answer eventually when they get tougher, which is kind of meh.
The look is nice, the music relaxing, and the controls okay.
All in all, decent, seems to be a lot of levels, which is nice. One thumb up.
ADDENDUM: 102 minutes start to finish. Could be better, not as educational as you might think because it really doesn't make you see the make in two the way I had hoped it would. Also it would be nice if it would let you examine the board better after it was over. Several of the solutions seem questionable. Still, fun enough for less than fifty cents.

70/100 Definitely quite a bit harder than the first one, and therefore not quite as much fun. Good puzzles though.