Trigonon ($0.99) by Just Funny Games S.r.l. is a very unique puzzle game where small black balls must be guided to blue, manually activated portals, in as little time as possible.
The balls are supposed to represent thoughts that must be captured by positive energy wells, but whatever the background story of the game, it sure is fun to play.
When the game starts, one or more black balls are immediately released and start moving. When it looks like the black ball is about to pass over or near a blue portal, give the portal a tap to activate it. It will take a few seconds to activate and will deactivate after a few seconds more.
Most of the time, however, the balls will not naturally move near the portals and it will take some work to get them there. This is done through the use of barriers. By tapping and dragging anywhere on the screen, you'll be able to place a barrier. In addition to choosing the location, you can also rotate the barrier to choose its orientation.
The barrier won't be set until you tap the check mark to confirm its placement. After confirming, the barrier can be rotated into a new orientation, but can't be dragged to a new location. However, it can be deleted at any time. The only problem would be the waste of time, which will affect your final score drastically.
There are five sectors available and each has its own levels and challenges. For example, in the first sector, a portal can be activated at any time, but in the second sector, positive energy must be accumulated to power the portal's activation. This is done by making a ball collide with small blocks that contain the required energy.
Each successive sector is unlocked by earning the required number of points. To maximize the points you earn, you'll have to complete each level as quickly as possible.
Trigonon offers a simple idea, but provides a fun and unique challenge that will have your attention for a good while. I suggest you give it a try.