GlenTris is a simple but enjoyable game a la Tetris in which you must place the falling blocks in the field in a way to form lines to score points and eliminate them from the field. Like in the original Tetris, the blocks can be rotated and you can also press the Spacebar to drop them quickly. When you reach a certain amount of points, you advance to the next level. Sadly, all the levels look quite the same, and the only difference is that the bricks fall faster as you progress to levels, giving you less time to think where you want to place them.
The game allows you to select the starting level, which is great. However, if you are a beginner, I suggest that you should start from the first level. You can also customize the piece rotation to be clockwise or counterclockwise, and you can mute the sounds. If you want to make the game more challenging, you can set the game to add as many junk rows as you want, these are extra blocks added in any form. Sounds are simple but nice, and unfortunately, the game doesn't include music. As you can see graphics are very simple, but yet attractive.
To sum up, if you are a search for a simple but enjoyable puzzle game to pass the time, GlenTris may turn out to be interesting for you.