Tetris Friends

Tetris Friends is a Tetris game available on its website and Facebook.

Gameplay details

 * ARE: No
 * Initial actions (IRS,IHS): Yes (must be unlocked)
 * T-Spin detection
 * Website version
 * 1989 and N-Blox mode: None
 * All other modes: 3-corner T
 * Facebook version
 * Ultra, Battle+, and Battle+6P 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.

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

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.

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.

T-Spin with wall kick is allowed even if it is played in Facebook version. However there are some graphical glitches. If you perform TST, only the score marker (the floating "+1600" text) will be displayed.

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.

Battle 6P (Battle+6P in Facebook)
Fight against five randomly selected opponents for 2 or 3 minutes. You can select a map. (the initial block patterns, as seen in TOJ)

Arena
This mode features realtime multiplayer between 2-6 players. Players earn points by winning and advance through a ranking system. There are currently 20 player ranks and 4 player classes.

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.

1989
This mode simulates classic GameBoy version of Tetris, but it's not so accurate. For example, DAS is somewhat faster, the gravity at level 15 is slower than original, and it has lock delay. Both A and B type game can be played, but B-type game doesn't have a separate leaderboard.

Acorn Drop
IceAge themed 150 lines marathon game. All pieces have same colors AND designs.

N-Blox
It's not a real game mode, but can be played in website version. You can't change keyboard mappings in this game.

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, and requires an account to play.