The game is intriguing as it is the first totally free solitaire game that allows you the possibility of winning cash. This is good, but upon further playing and deeper inspection I am noticing some odd things.
The competition in this game, is certainly skill based, but I have played hundred upon hundreds of games and have yet to see any proof that I am actually playing against another human being. I suspect that I am playing against bots, which would mean the vast majority of the time the money going into the game/system is going to be staying there, and because bots can produce inhuman game times very consistently the odds are stacked heavily against the player.
I am a fairly skilled player, and have played competitively for years, but currently my opposition requires me to complete my games in under 40 seconds virtually every game to win even on the free levels, which is extremely suspicious. Human opponents have a much higher variation in their games. This is certainly fun to play, but I would caution against investing your actual money until the company can provide evidence of a level playing field as most other games in the genre do by allowing player communication, video replays, and the ability to check the profiles of your opponents.