You are a glacier. One visit, one year.
The valley waits for you between visits.
Once a day, you get one choice: how the glacier spends this year.
Accumulate — snow piles deep and the ice leans on the valley floor. Surge — the whole width scours at once, fast and rough. Carve — favor one wall and steepen it while the other rests. Retreat — the front pulls back and drops what it was carrying right where it stood.
Watch the year happen, then go. There's no timer and no wrong answer.
Come back tomorrow for the next year. Come back next week — the ice will still be exactly where you left it. Absence is never punished; it's just a year that hasn't happened yet.
After sixty years the cirque is finished: a valley shaped entirely by your choices, one a day. Keep it as a postcard, or carve a new cirque and start again.
Tap the ice to skip ahead.