Touch Arcade Writes:
The game is a port of a Jailbreak version by the same name. This free game offers a no-frills Tetris experience for those who don't want to spend $9.99 for the official version [App Store].
Touch controls move pieces left, right, down and even up, while tapping allows you to rotate your piece. The actual game is nicely implemented with attractive graphics and smooth animation. Tris also offers a global high-score system so you can compare your play with others. A lack of sound effects or music, however, makes the gameplay a little unsatisfying. Fortunately, you can play your own music in the background.