About Inertia
Slide a green glass ball through a stone maze and collect every pale crystal. You choose the direction, but walls, edges and brass rings decide where the ball stops.
Explore 1,621 original boards in six open collections. Start with simple turns, then combine diagonals, stop rings and mine avoidance. Revisit a solved board to find a shorter route.
How to play
- Goal
- Collect every crystal without hitting a mine.
- How it ends
- Win after a safe slide collects every crystal. A mine ends the attempt; Undo can take you back.
- Record
- First-solve time and fewest moves. Undo keeps the cost of earlier slides. Restart keeps the first-solve clock.
- Choose any board, then one of eight directions. The ball slides until a wall or edge stops it on the previous square, or a brass ring stops it on entry.
- Passing through a crystal collects it without stopping the ball. Collect them all and finish the slide safely to win. A mine ends the attempt, even if you passed the last crystal earlier in that slide.
- Diagonal gaps between side walls are open. Brass rings stop the ball on every visit. Plan your next direction from the square where the ball will come to rest.
- Undo restores the previous position and crystals, including after a mine, but keeps the cost of earlier slides. Restart clears the route and move count while keeping the first-solve clock.
Controls
| Input | Action |
|---|---|
| Tap or click a direction button | Slide in one of eight directions |
| Arrow keys / Q E Z C | Slide straight / diagonally |
| Numeric keypad 1–9, excluding 5 | Slide in the matching direction |
| U / R | Undo / confirm Restart |
| Escape | Close a panel or return to Boards |
Tips
- Plan the stop A crystal is a pickup, not a brake. Look beyond it to the wall, edge or ring that ends your slide.
- Check the whole lane A mine beyond the last crystal still ends the attempt.
- Try a shorter replay First time and fewest moves are separate records; a thoughtful replay can improve moves.
Good to know
Progress saves in this browser. Menus and same-page board visits keep the first clock running. Reopening the page restores progress with local-only time; shorter replays can still improve moves. Another tab on the same board plays temporarily. Very long routes warn before their record or save limits. Music, effects and reduced motion have separate settings.
Watch how to play
Questions
Do I need to stop on the last crystal?
No. Pass through it, then finish that slide safely. A mine later in the same slide still loses.
Is there only one route?
No. Different routes can clear a board. Try to reduce your cumulative slide count; undone slides still count.
