I like the general gameplay, and I like the ability to change the color scheme and background (though the original color scheme is still my favorite!).
I found the controls a little clunky at first, but I definitely prefer them to faster controls that might lead to more mistakes, and I got used to them pretty quickly. Good job on that! A lot of games like this have controls that make it really easy to make (frustrating) mistakes, so HUGE kudos on making tile-setting more deliberate.
The only thing I'm not a huge fan of is that when I've selected a tile, all available spaces for me to set it down on flash. Having them change color to make it more clear to the player which spaces are open isn't a bad idea, but the flashing is distracting and hurts my eyes after a bit, even though I plan where I want to set tiles before selecting them to minimize the time in between selecting and setting down a tile. I wish there was an option to turn it off - if there is and I somehow missed it, please let me know.
Overall - quite nice. I like the several levels of opponent AI and simple but strategic gameplay, and the controls are great.