Low has 24 crossings, Medium 18, Hard 12. Harder modes have lower survival chances and higher multipliers. Traffic illustrates the outcome; this is not a timing challenge.
90% theoretical return for any fixed cash-out step, before rounding. Multipliers equal 90% divided by cumulative survival probability, rounded down to two decimals. Payout uses that displayed multiplier and rounds down to whole credits. This browser prototype uses virtual credits; it is not a production real-money gambling system.
Bet limits: ₩100–₩30,000 virtual credits. Bet and risk stay locked during a round. Sound starts only when enabled.