Elementum is an upcoming puzzle game being released by indie developer One Thing Studios. I played the demo recently and really enjoyed its mechanics and can see it being a decent hit for the developers. The concept is simple but there's really a ton of room for potential. I'm looking forward to its full release soon and hope the full game is as good as the demo.
By the way, the demo works perfectly in Wine on Linux, so hopefully there aren't any incompatibilities introduced with the full game.
If I had to describe Elementum, I would call it a mix of Peggle, Bejeweled, and air hockey. You're basically presented with a bunch of balls (or particles) you need to destroy. To remove them from the board, you need to shoot a ball from the outer edge into the mix and group at least three of the same color together. If the shot ball comes in contact with another ball, they switch places: the shot ball is now at rest and the stationary ball is ricocheted off. With a normal shot, one ball goes in and one ball goes out. The ball heading out must now be caught though by the device that shoots balls in. It may sound a bit confusing but it is really very simple, check out the screenshot.