Hourglass Swap
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Flip sand timers in sequence to measure exact target times.
About Hourglass Swap
Flip sand timers in sequence to measure exact target times. 30 brain-teasing timing puzzles across 6 difficulty tiers using classic water-jug mathematics.
Description provided by GameZipper.
How to play
- Each level shows a target time. You need to measure exactly this amount using your hourglasses.
- All hourglasses start with sand on top flowing down at 1 unit per second. Watch the sand levels change.
- Tap any hourglass to instantly flip it. The top becomes the bottom and vice versa. Time your flips carefully.
- Win when any hourglass has exactly the target amount in its top or bottom bulb. Fewer flips earn more stars!
Controls
This game supports touch, keyboard, mouse input; the exact controls are explained inside the game.
Questions
- How do you play Hourglass Swap?
- Each level gives you 2-4 hourglasses with different sand capacities. All start full on top and sand flows down at 1 unit per second. Tap any hourglass to flip it. Your goal is to reach a moment when some hourglass has exactly the target amount of sand in it (top or bottom).
- What is the math behind hourglass puzzles?
- Hourglass puzzles are based on the same mathematics as the classic water jug problem (Bezout identity). With hourglasses of capacity a and b, you can measure any multiple of gcd(a,b). The puzzle generates levels where the target is always achievable.
- How many levels does Hourglass Swap have?
- 30 levels across 6 difficulty tiers. Tier 1-2 uses 2 hourglasses, Tier 3-4 uses 3, and Tier 5-6 uses 4. Each level is mathematically verified solvable via BFS.
