I've played the web-version of the game and want to share my thoughts with you. I like the gameplay, it reminds me of minesweeper.
But I also have some critics.
First of all, I don't like the look of the game, it looks like something straight from the 90s. When I openwd the thread and saw the screenshots, I was tempted to close the thread and forget about the game, simply because it looks boring. But then I decided to give it a try.
There are some beautiful minimalistic android games out there which got a lot of attention because of their style. Have a look at "ballmaze lite" in the playstore, it would fit perfectly for your game! I made a quick mockup to show how I think it would look a lot nicer (the first picture).
Second, when you first start the game you don't have a clue what to do. I had to quit the game and read the help pages (they are not very nice to navigate and read) to know how to play. Many people want to jump into the game without reading 7 (or so) pages of a helpfile. I think this scares a lot of people of... I would remove the help section and replace it with a tutorial mode. In this mode (second picture) you have a small grid to start with. After loading the tutorial you could draw an overlay over the top-left square (which is fixed color and has the number 2) and write something like
"this square has a fixed color which cannot be changed. The number shows how many neighbour squares have the same color. This includes horizontal, vertical and diagonal neighbours. Thus a square can have up to 8 neighbours"
when the player taps the screen a next overlay shows up on a grey empty square and it explanes that the player has to change their colors according to the numbers and neighbours. A third overlay could explain the color-picker at the bottom and its function and the numbers in it. A fourth overlay could explain the red border around wrong colored squares. Then the player can fill out the simple grid and should know enough to play the game.
I hope this is helpful for you.