If you succeed, you make it through at a rate depending on how well you succeed. If you crit fail, you become stuck for at least a minute. If you fail, nothing happens.
How long does it take to perform the Squeeze action? Does the time that needs to be invested depend on the result of the check? How much time is wasted if you fail? How long does a crit fail take to get you stuck?
How long it takes is based on the distance. 5 feet per minute on a success and 10 feet per minute on a critical success.
Crit fail you get stuck for one minute.
The only ambiguity is on a fail result. I would probably go with immediate retry. Because otherwise the fail result is nearly identical to critical failure result.
If you are fine with regular fail and critical failure meaning no squeezing for one minute, that would also work. There is the difference that if you get attacked, the regular fail means that you aren't stuck in the crevice for the entire battle.
I wouldn't recommend more than a minute delay on regular fail.
I thought the fail might allow for an instant retry, but this is an Exploration activity, so it necessarily takes more than a turn and usually can't be used in combat. A minute wasted makes more sense to me.
Yeah. Like I mentioned, it is unspecified in that case. So, it is up to the players at the table - especially the GM - to decide how long a failure result slows things down.