Like Mario game, Tertis is one classic game that has been around for a while. You can play Tetris game online for free without need to download anything. Online version of this game has all elements of traditional Tetris game with different shapes of colorful blocks falling down.
You need to rotate the falling block(s) and arrange them perfectly. Use Left and Right arrow keys to move the block. You can rotate and change shape of block by using Down arrow key. It has different levels of play and scores to keep check on your performance. Get into some fun play with online Tetris game, wanna play?