Swap is the classical match-3 game in which you need to swap two adjacent items in order to align three or more of the same color and make them disappear from the board. For every match you create, you will be given points. The more items you align, the higher your score will be. The game offers four modes: Rush, Classic, Million, and Relax. In Rush, you will have 60 seconds to break the high score, whereas in the Classic mode, you will have 5 minutes. On the contrary, in Million mode, you will need to reach 1 million points to win, and in the Relax mode, you play for fun until you get tired of the game.
No matter which mode you select, you will have four difficulty levels to choose from. From time to time, some items will contain a power-up that you can use by creating a match with them. The power-ups help you clear complete rows and columns, 3x3 areas and others. Sadly, the game offers very simple graphics and sounds, and the music is suitable, but repetitive, and it gets annoying after some time.
In conclusion, I think the price is a bit high for a common game like this one, which really does not have anything original or special. I am sure you can find better similar games for the same money or even less.