|Developer(s)||Blue Planet Software|
|Publisher(s)||The Tetris Company|
|Playfield size||10 × 20|
Tetris on tetris.com is a free, ad supported, web based guideline game. It was developed and released in celebration of Tetris's 30th anniversary.
The game follows the rule set of the Marathon mode known from older games. It can be played with keyboard, mouse, or touch controls. Controls are customizable and so are auto-repeat delay and auto-repeat speed (ARR). The game features three different versions of Korobeiniki as the background music, and has a local high score table where you enter your initials.
Marathon mode can be started at levels 1, 5, 10, 15, 20 or 25. Speed maxes out at level 30. The level increases every 10 cleared lines. For example, it takes 140 line clears to reach level 15 when starting at level 1, and 100 line clears to reach level 15 when starting at level 5. Starting the game at level 1 or level 5 is recommended for scoring purposes. The game ends when the player tops out or clears at least 300 lines (if starting on level 1).
When the level increases, so does the gravity. The gravity reaches its maximum (20G) at level 20. Afterwards, lock delay decreases (whereas the initial lock delay is about a half second), while ARE is still constant. The game uses move reset lock delay, in which a movement or rotation of a piece will reset the delay, making it still active until either the delay runs out or the piece is moved or rotated 15 times.
Scoring follows the current system for guideline games.
Tetris (tetris.com) began development on July 2014, as a replacement for the existing N-Blox game found on Tetris's official website. The prototype version initially required Unity Web Player to run the game.
The finished version went live on February 2015, and the game originally ran on Adobe Flash Player before switching to HTML5 on January 2017.
On March 2018, a re-skin of the Tetris.com version featuring American singer-songwriter Madilyn Bailey as a promotion for her single "Tetris" was quietly launched.
On April 17, 2019, Tetris and Sanrio announced a multi-year partnership, and a re-skin of the Tetris.com version featuring Hello Kitty and several other Sanrio characters was released on June 3, 2019. It was later discontinued on June 28, 2021. 
Shortly after, the main version's intro screen was modified to include the then-newly-launched Tetris logo; otherwise, gameplay mechanics and graphical interface remain the same.
The game received two updates in 2021: the first consisted of adding perfect clear and combo score bonuses to the existing scoring table since April 5th; the second adds visual effects for piece drops and line clears (taken from the Hello Kitty version) since September 1st.