That's Block is a block puzzle game. The player's goals are to create eight-block lines on an 8x8 grid with polyomino shapes, earn the highest score possible, and collect enough stars per level to obtain achievement titles.
The game presents the player with a set of three shapes to the right of the grid. The player must use the entire set before receiving another one. They monitor their score next to a gold crown in the center area above the grid. They monitor their current achievement rank in the upper-left area.
The player earns points and stars faster when they complete a streak of lines. The game displays their progress as multipliers under the word Combo on a pulsating pink heart in the lower-left area. Unlike some games, the player doesn't immediately lose their streak if they can't make one line after another. They're given an extra move to complete the task.
That's Block challenges the player by increasing the achievement score requirement. It also presents them with complex and mirror shapes in a set. For example, it offers them two identical parallel bars as a single shape.
If the player meets their achievement goals, they receive a new title, and the game displays a new rank icon. Titles include Stacking Trainee, Beginner Assembler, Combination Apprentice, Assistant Stacker, Shape Assembler, Combo Operator, Field Designer, Shape Architect, Field Tactician, Lead Combinator and Block Master.
After the player reaches the master level, they must then obtain Pattern Maker, Combination Virtuoso, Lord of Blocks, King of Combos, Tetris Legend, and Emperor of the Cubes titles. That said, if they run out of moves at any time, the game bumps them back to the beginning and the Stacking Trainee position.
