I'd like to start this review by saying, the Ball wasn't a bad game, I just found myself bored a bit to often to confidently recommend.
The game itself functions well enough. I never encountered any game breaking glitches, never sank through the floor, lost the ball, or had a button simply not work. It plays just fine in that regard. The ball control is a bit wobbly in terms of getting it to shoot precisely, but it's very slight, and most of the puzzles allow for that little bit of wiggle room.
The puzzles are pretty easy, and never really force you to do any huge mental gymnastics. The hardest part of the game are the survival levels and those just involve surviving waves of enemies. The enemies are easy enough to kill (rolling the ball over them) but they're a non-threat for the the campaign and appear so sparingly in the campaign they almost feel a little out of place. They aren't there as a puzzle impediment like the turrets in portal, most times (a few exceptions), they're mostly just thrown at you to be a momentary antagonist.
The story is interesting. However you only get it through finding secrets and once you've clicked out of the text screen there's no way to recall that text without playing through the level and finding the secret again, so if you miss one that's unfortunate. The secrets themselves are easy enough to find, you just have to be patient and willing to hunt around for hidden alcoves and the like. They do however have a stage selector so if you really want to play a level over it's easy to do.
The game looks nice enough. The graphics are consistent, and I never saw any graphical glitches, but the ball itself is a bit annoying. Even transparent it's very noticeable and still impedes vision to a degree. The problem there lies in the design of the ball. The ball is made up of two parts. A round solid peice, and a complex framework. Everything fades out except for the framework, which there is a lot of, causing a sort of cage like effect on your vision.
Overall the game was alright. I don't regret buying it, or playing it. If you're looking for a game similar to portal, while this is in the same vein (logic puzzler), it isn't in the same league. If you want to have some fun walking through mildly Aztecian ruins, smashing some zombies, and solving some puzzles give it a shot.