When I played the first 40 levels of Sharp Minds, I didn't like it because it was too easy. Nevertheless I kept playing to experience the 'special powers'. The 'special powers' didn't start at the beginning. I think they start at level 41.
Some tiles have a little circle in the corner. Let's say a 3 has that symbol. If you use that 3 with other numbers to eliminate a 12, for example, then all the yellow 12's will be eliminated.
Other tiles have a little arrow in the corner. That power: if you swipe/add blue tiles up to eliminate a yellow tile, then all of the other yellow tiles - going in that direction - will also be eliminated.
Each level has a fixed starting field of numbers. However, when the blue tiles get replaced, they are replaced with random numbers.
Sharp Minds has 'hundreds' of levels and I've solved 141. This took about 3-4 hours to achieve. Yesterday I was in a 2 hour staff meeting, so I got a lot done. (Hope the boss doesn't follow this blog.)