How to Play Shape Stack
Each round presents six columns. At the top of each one is its target: a particular color and shape. Look at the large current piece, then place it in the column with the same combination. You can click or tap a column, or press its number key, 1 through 6. The next piece appears as soon as you place the current one.
The pieces come in five colors—cyan, yellow, pink, blue, and purple—and two shapes, circles and squares. A column might ask for a pink square while another asks for a pink circle, so checking the color alone is not always enough. Each column closes when its slots are full. The round finishes when every piece in the deck has been played or skipped.
How Adaptive Difficulty Works
Shape Stack has six levels and always shows six target columns. At level one, each column holds three pieces; capacity rises by one at each level, reaching eight pieces per column at level six. The deck contains exactly one matching piece for every slot and is shuffled at the start of each round.
After a round, accuracy of at least 85% raises the next level by one, unless you are already at level six. Accuracy below 60% lowers it by one, unless you are at level one. Otherwise the difficulty stays put. Your next level and best accuracy are saved in this browser, not in an account. Clearing this browser’s storage removes that progress.
Accuracy and the Skip Rule
A piece placed in the wrong column still takes up a slot there and counts as an incorrect placement. That can close a column before all of its own pieces have appeared. If the current piece’s matching column is already closed, a Skip piece button becomes available. You can also press 0 or Space when focus is outside the game’s buttons. Skipping is not available while the piece still has room in its matching column.
Accuracy compares correct placements with all placements you made; skipped pieces are counted separately in the results. A wrong move can therefore affect both your score and which later pieces can reach their proper column. There is no time limit, so it pays to read both parts of a target before choosing.
Why Sorting Games Hold Our Attention
A sorting puzzle gives your eyes a small but deliberate task: notice a feature, compare it with a set of alternatives, and make a choice. Here, the two features are color and shape. Distinguishing a blue circle from a blue square calls for visual discrimination; ignoring other tempting columns while finding the exact match calls for selective attention.
Those terms describe what you do during play, not a promise of a health benefit. Shape Stack is a casual game rather than a test or treatment. Its appeal is the satisfying rhythm of checking a piece, making a decision, and seeing the columns gradually fill.
Tips for a Cleaner Round
- Check shape after color. Two targets can share a color while asking for different shapes.
- Watch nearly full columns. An incorrect placement can close the space a later matching piece needs.
- Use the shortcut numbers. The number shown on a column matches the key that selects it.
- Pause when a skip appears. It means this piece’s own column is closed; other open columns would count as wrong placements.