The Ball is another good first person puzzle game. The main reason my rating is low is because of the cost of the game. The game is basically just a standalone version of a UT3 mod Desura.com
Whenever you hear "first person puzzle game" you probably think Portal, most other first person games that include puzzles more fall under action because puzzles are a side thing. The Ball is another good first person puzzle game that should not be overlooked.
The mechanics to this game are simple, you walk around, you can jump and swim, and you can push and pull the ball. I can't quite remember the story or how you get the ball as I've just been playing this game a little bit from time to time.
For all puzzles in the game you will need the ball (mostly to push buttons for you). There are parts where you need to leave the ball behind and go solve a puzzle to come back and carry on, those parts I have never felt so helpless in a first person game. Here I am, trapped in ancient ruins, my only defense (or companion for that matter) is a giant ball bigger than me and it can't come with me :\.
The ball is also your only defense against enemies (yes, there are enemies in this puzzle game) you can push it to roll them over or wait until they get close and run them over.
All in all a solid game, built on the Unreal Engine 3, but the 19.99 price tag is probably what will kill this game for most people, 9.99 to no more than 14.99 this game would be worth it but a whole 20 bucks? Watch for sales