Four boards stacked in a cube. Get four in a row: across a board, straight up through the boards, or slanting right through the cube! With 3D glasses the layers float one above the other.
🤖 Robot ladder
🎨 Piece colours
Do you have 3D glasses? Red-green, red-blue and red-cyan glasses all work.
You can change this any time from the menu.
3D GLASSES
Your glasses
Check the 3D
How deep?
Less depth is easier on the eyes. More depth pops out more.
1. Hide the green bar
Put the glasses on and cover the eye behind the green lens, so you look only through the red lens. Slide left until the green bar disappears.
2. Hide the red bar
Now cover the eye behind the red lens, so you look only through the green lens. Slide left until the red bar disappears.
3D mode is just a fun way to play. If your eyes feel tired, take a break or play without glasses.
HOW TO PLAY
You are the balls and the robot (or your friend) is the cubes. Take turns tapping an empty square to put your piece there.
Get a whole line of your pieces to win: 3 in a row on the small 3×3×3 cube, 4 in a row on the big 4×4×4 one.
Lines can go across one board, straight up through all the boards, slanting up through the boards, or from one corner of the cube to the opposite corner. The big cube has 76 lines!
Drag sideways (or tap 🔄) to turn the cube and check every line. 💡 Hint shows a good square. ↶ Undo takes back your last move.
Beat a robot to open the next one. Beat each robot 3 times for ⭐⭐⭐. Wins earn coins for piece colours.
Pro tip: make two lines of 3 at once (a "fork"). The robot can only block one!
HOW 3D WORKS
Try this: hold a pencil out and look at it with one eye, then the other. It jumps. Your brain uses that jump to tell how far away things are: stereo vision.
The game draws the cube twice, from two eyes a little apart, once in red and once in green (or blue). The glasses give each eye its own picture, so the boards really stack up in front of you.
On a flat board there are 8 lines of three. In a 3×3×3 cube there are 49, and in a 4×4×4 cube 76. Thinking in three dimensions lets you see many more lines at once!
Computers were taught this game in the 1960s and 70s, and in 1980 a computer proved that the first player can always win the 4×4×4 game if they play perfectly. Nobody can remember that perfect plan, so keep practising!