Tetris Friends

Tetris Friends is a Tetris game available in it's website and Facebook.

Gameplay details

 * ARE: No
 * Initial actions (IRS,IHS): No
 * T-Spin detection
 * Website version
 * All modes: 3-corner T
 * Facebook version
 * Holiday mode and Battle 2P mode: 3-corner T
 * BlockStar mode: None
 * All other modes: 3-corner T no kick
 * Combo bonus: Yes

Marathon
Standard marathon mode with 15 level limit.

In website version, this mode always starts from level 1.

In Facebook version, starting level is selectable. If you reach certain level, you can unlock additional skins.

Sprint
Clear 40 lines as fast as possible. Level is not selectable and fixed to 1.

Sprint 5P
Compete with 4 opponents in Sprint mode. Opponents are just the previously recorded play, and randomly selected based on your current rank.

Survival
This mode features similar objective as marathon, but has different goal system. Level advances by clearing every 10 lines. After you beat 20th level, you'll enter the "Bonus Level". The bonus level is semi-invisible challenge, and the game continues until you top out. This mode is available only in website version. In Facebook version it was available as Holiday mode, but it's not available now.

Ultra
2 minutes ultra mode. Score as many points as possible within 2 minutes. In Facebook version, music is selectable from 5 songs. In website version, however, only "Midnite" music is available. This mode was formerly known as Tetris Solo, and 3 minutes mode was also available. Level is not selectable and fixed to 1. Your score will not be recorded if you top out.

Battle 2P (Battle+ in Facebook)
Fight against a randomly selected opponent. As in Sprint 5P mode, opponents are just the previously recorded play. Garbages doesn't have a hole. You can remove it by attacking your opponent.

BlockStar
This mode is remake of the first Tetris game released on Facebook. It has classic game elements: no hold piece, no ghost piece, no lock delay, only one piece preview, endless game time, and more. This mode is available only in Facebook version.

Scoring Strategy
Tetris Friends has a goal system where the way to get to the next level is to clear a certain number of goal lines that increases as the levels do. The optimal way to acheive a high score is using the Single-single combo strategy:

Post specifically about facebook tetris scoring strategy

YouTube - Higher Tetris Splash and Facebook Tetris marathon score's