Plex Lite has recently been unleashed on the Windows Phone Marketplace and is the free version of the popular game Plex. Plex Lite has access to all twenty-four levels of the Adventure Mode but lacks the Survival Mode which is found on the paid version.
Plex Lite has you clearing tiles off a 3D sphere by placing matching tiles on top of existing tiles of the same design. There are bonus tiles that appear along the way to help you with the adventure. Each level must be cleared within a certain time limit and the faster you clear the sphere, the higher your score.
The game screen has your placement tile displayed in the upper right corner, rotation arrows to turn your sphere in the bottom right and your timer (the blue bar) along the left side. You'll have to rotate the sphere until the spot where you want to place the new tile is highlighted in the center of the screen. Once that is accomplished, tap the screen and the new tile drops.
Plex Lite is just addictive as the paid version and worth a try. Plex Lite is ad supported but only on the transition screens. The game screen is ad free.