Block 21

• Tap the screen or click the mouse

1. 1Identify the goal first. Look for a target, counter or outline that tells you what a finished stage looks like.
2. 2Make a move you can reverse, then see how the board reacts. Most puzzles let you undo or restart freely.
3. 3Group similar pieces or clear blockers early so you have room to work later in the stage.
4. 4When you solve a stage, note what the trick was; the next few stages will usually build on it.

• Free to play, nothing to install, no account needed
• Loads in the browser tab and opens full screen when you press Play
• Plays best with the phone turned sideways or on a wider screen
• Touch controls on phones and tablets, mouse and keyboard on a computer
• Listed under Puzzles

Because it fits into the gaps. Block 21 does not need a download or a login, and a stage takes about as long as waiting for a kettle. It is also one of the few kinds of game that leaves you feeling slightly sharper rather than drained.

Players of any age who like a quiet challenge. Grandparents and grandchildren can share it. People who commute, anyone who enjoys logic problems, and those who want a game that does not demand quick fingers.

Do I need a fast computer to run Block 21?

No. Puzzle games are light on graphics and run fine on older laptops, basic tablets and most phones. A current browser matters more than hardware.

Can two people play together?

Puzzle games here are generally single player, but they work well passed back and forth, with one person solving and another suggesting moves.

Why did my progress disappear?

Progress is stored in the browser rather than an account. If you cleared browsing data, used a private window, or switched devices, the game would start fresh.