Tetra Online is a fast-paced puzzle stacker. The game requires quick reflexes, with the ability to adapt to situations being essential. There are many modes to play, including singleplayer and multiplayer modes.

Singleplayer

• Endurance is the standard singleplayer mode of the game. As the game goes on, the pieces start falling faster. The player can play to a goal or play forever!
  
• 40L is the most competitively played mode. It requires the player to clear 40 lines as quickly as they can. Players will use every tactic and every optimization to shave even a second off their time!
  
• Score Challenge requires the player to rack up as many points as they can within the time limit! To score more points, they will turn to different strategies such as clearing many rows at a time without mistakes, twisting pieces into tight spots and clearing many lines successively.

Online Multiplayer

• Puzzle Duel is the main, competitive mode. It pairs two players against each other in a ranked first-to-two match. The winner will rank up and loser will rank down. Leaving prematurely awards players a loss.
  
• Puzzle Arenas are a mode where players can play against their friends or random people. They can create rooms and tweak various settings to their liking.