TETR.IO

TETR.IO is an online browser game made by osk (as in ki-osk) currently in alpha development. It mainly features competitive one-on-one gameplay with a limited set of singleplayer modes. It was originally INDEV on Feburary 19, 2019, went INFDEV on January 31st, 2020, and went Alpha on March 22nd, 2020.

"TETR.IO" has multiplayer and singleplayer modes. There are 4 singleplayer modes and 3 multiplayer modes.

Singleplayer Modes
Singleplayer has 4 modes, which are Sprint, Blitz, Zen, and Custom. There used to be a 5th one, called "5,000,000 Blast", to celebrate the game reaching 5 million members.

Sprint
Sprint is your basic 40 line speedrun. Players are given a board of 10x20, and are tasked to clear 40 lines in the fastest time they can. While nothing new, you can do specific tasks in this game mode to unlock 3 Badges.

These tasks are:

Secret Grade: Complete the Secret Grade pattern and you will be awarded the Secret Grade badge.

20TSD: Clear 40 lines using 20 T-Spin Doubles. Doing this will award you the 20TSD badge.

10 PCs: Make 10 Perfect Clears in sprint. Not all PCs need to be 4 line. There just needs to be 10 PCs in the run in order for you to get the 10 Perfect Clears badge.

Note that Secret Grade is not specific to 40 Lines and can be cleared in any singleplayer mode except Zen.

Blitz
Blitz is your 2 minute score attack run, like Ultra. The twist is that there is a leveling system, that multiplies your score with each level passed. Not only do these Levels multiply your score, they increase gravity as well. It takes 3 lines to get to level 2, 5 lines to level 3, etc. Oddly, at level 11, the goal to level up (to level 12) increases by 3, (24) but then returns to the basic +2 format. (Level 12 to Level 13 would take 26 lines)

Like in other score attacks, Perfect Clears award a large amount of points. Here is the score chart for each action.

Unaffected by the level multiplier, Soft Drop gives you 1 point per cell dropped and Hard Drop gives you 2 points per cell dropped.

Zen
In Zen, the player can choose between many settings in the Zen menu. It is similar to custom, but with a levelling system. Usually used simply to relax or to train.

Custom
In custom, the player can specify even more settings than Zen, such as board size, rotation, etc. Usually used just for fun.