Its price is justified by:

1. Size - portability. It is a beautifully designed slim construction that fits everywhere.
2. Hall effect joystick, theoretically much better quality and durability over time compared to conventional analog ones
3. Battery, lasts many hours
4. Quality construction

I haven't tried many games. Anything that mainly involves simple controls like platformers is excellent and comfortable. In slightly more "demanding" games for controllers, like football where you need to press 3-4 buttons simultaneously along with the joystick, it's not convenient, resulting in having to put your fingers/hands in an awkward position.

Nevertheless, you know what you're buying, so mainly for the above 4 reasons I give it 5 instead of 4 stars. In short, I would say it's for light games like puzzle-platformers, while for action/shooter games, only under certain conditions.